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Home My WebLink About20233779.tiff .1,JZZ6171 Weadt;be /a-0,9e,-,2,6a3 WELD COUNTY CODE ORDINANCE 2023-16 IN THE MATTER OF REPEALING AND REENACTING,WITH AMENDMENTS,CHAPTER 8 PUBLIC WORKS,OF THE WELD COUNTY CODE BE IT ORDAINED BY THE BOARD OF COUNTY COMMISSIONERS OF THE COUNTY OF WELD,STATE OF COLORADO: WHEREAS, the Board of County Commissioners of the County of Weld, State of Colorado,pursuant to Colorado statute and the Weld County Home Rule Charter,is vested with the authority of administering the affairs of Weld County,Colorado,and WHEREAS,the Board of County Commissioners, on December 28, 2000, adopted Weld County Code Ordinance 2000-1,enacting a comprehensive Code for the County of Weld, including the codification of all previously adopted ordinances of a general and permanent nature enacted on or before said date of adoption,and WHEREAS,the Weld County Code is in need of revision and clarification with regard to procedures,terms,and requirements therein. NOW,THEREFORE,BE IT ORDAINED by the Board of County Commissioners of the County of Weld,State of Colorado,that Chapter 8 of the Weld County Code be,and hereby is, repealed and re-enacted,with amendments,to read as follows. CHAPTER 8 PUBLIC WORKS ARTICLE I-Snow and Ice Policy Amend Sec.8-1-20.Snow watch plan. A. During normal working hours,sanding and/or plowing operations may be initiated by the Director of Public Works or the on-duty Snow Boss. B. In order to ensure that sanding/plowing operations are initiated in a timely manner at other than normal working hours, feedback regarding road conditions by Sheriffs Office Deputies and any other agency,including the Colorado State Patrol,shall be sent to the Weld County Regional Communications Center(WCRCC).The WCRCC shall then notify the scheduled on-duty Snow Boss.The Snow Boss shall then initiate sanding/plowing operations accordingly. Amend Sec.8-1-30.Snow removal priorities. A. Priorities:Clearing of roads shall occur according to the following order of priority: 1.thru 6.—No change. PAGE 1 2023-3779 ORD2023-16 7. Collector roads. 8. Local roads,including subdivisions and unincorporated towns. B. Command and control. 1.—No change. 2. Control of operations shall be exercised at the Public Works Department Operations Center (PWDOC). Communications between Snow Boss and operators shall be according to the following methods:1)County Radio System; 2)cell phone;3)CB radio.The Director of Public Works shall be in charge of snow removal operations and shall staff the PWDOC as necessary to carry out operations efficiently.This authority shall be delegated to the assigned Snow Bosses. 3. Any calls for emergency services received at the PWDOC shall be forwarded to the appropriate agency. 4. All incoming calls regarding snow removal or emergencies shall be routed to the PWDOC from dispatch or in-house Public Works staff. C. Operations. 1.—No change. 2. If weather information indicates that operations are anticipated in advance of the approaching storm,the Director of Public Works shall direct specific operators to be at work and ready to commence operations as soon as practical.If more than two(2)days of continuous operations are anticipated,no operator shall work more than twelve(12)hours in a day without approval of the Director of Public Works. 3. Status of all snow removal operations shall be maintained at the PWDOC.Reports shall be made to the Public Works Emergency Notification Group intermittently throughout the snow event.These reports shall be directed by the Director of Public Works or on-duty Snow Boss. 4.—No change. 5. If an abandoned vehicle is blocking the roadway,the operator shall radio in the location,license plate number and description of the vehicle to the PWDOC.The PWDOC shall contact the Regional Communications Center, informing the Dispatcher that a hazard exists and the vehicle should be removed from the County road right-of-way.Dispatch shall contact the Weld County Sheriffs Office for appropriate action. 6. No school property or private roads or driveways off the County rights-of-way shall be cleared by County equipment,with the following exceptions: PAGE 2 2023-3779 ORD2023-16 a. If requested in writing,by a school district,and approved in advance by the Board of County Commissioners. b.—No change. 7. Plow trucks shall primarily be used to remove snow and ice on paved roads and have designated routes or zones but may be assigned otherwise as needed. 8. Repair and maintenance of all Public Works equipment shall be furnished by the Weld County Department of Fleet Services during a snow event.Personnel shall be on standby or on duty,as directed by the Director of Fleet Services. 9.—No change. D. Planning and preparation. 1. All supervisors of units providing snow removal are responsible for ensuring that equipment is ready and personnel are briefed on their duties.Prior to a snow event, each piece of equipment shall be inspected with its plow and spreader to ensure readiness.All other equipment,such as tire and tow chains,route maps and vehicle lights,shall also be inspected at this time. 2. Fuel stocks at outlying satellite facilities shall be monitored by the individual zone operators immediately prior to a snow event and status reported to Fleet Services. If a fuel delivery is necessary during a snow event,the Snow Boss may direct the delivery route be cleared on a priority basis. Amend Sec.8-1-40.Contracting for additional resources. In cases of EXTREME EMERGENCY and where County resources cannot maintain safe traveling conditions,it may be necessary to obtain additional equipment from Contractors. A. Authorization for contract. 1.—No change. 2. The Director of Public Works or authorized agent of the Board of County Commissioners shall follow the emergency procurement process in Chapter 5 of the Weld County Code. B. Contracted equipment command and control.Control of contractor equipment shall be exercised through the PWDOC.The Director of Public Works or the on-duty Snow Boss shall coordinate and control the efforts of all contractor equipment. PAGE 3 2023-3779 ORD2023-16 C. Operations. 1. County and contracted workforces shall be employed to maximize the efficiency of the snow removal operation.Contracted equipment may be paired with County equipment to take advantage of County radio control. 2. As soon as it is apparent that County forces can manage resources for the remaining snow event,the Director of Public Works shall terminate contractor operations. 3.—No change. 4. Contractors shall submit invoices to the Department of Public Works to receive payment for time and costs. Amend Sec.8-1-50.Response plan for extreme snow and ice events. The following policy sets in place criteria for managing snow and ice removal efforts on the County roadway network during exteme weather events. A. Weather event definition.Snow events are categorized using a storm level scale based on reports from the field as to the severity of conditions,as well as other methods, including forecasts,satellite images,weather stations and common sense.With the vast expanse of Weld County,storm levels may vary depending on conditions in that area.The levels of storms are defined below: 1. Level 1: Extreme weather conditions.Snow removal efforts shall cease,and equipment shall retreat to designated recovery stations located throughout the County for further instructions and redeployment as conditions warrant.Level 1 may be declared by the on-duty Snow Boss with the concurrence of the Director of Public Works, the Commissioner Coordinator or Alternate Commissioner Coordinator for Public Works.When redeployed,resources shall be committed to predetermined priority snow routes.Notification of a Level 1 Condition or any road closures shall be communicated to the Regional Communications Center and the Public Works Emergency Notification List. 2. Level 2:Snow Removal Operations shall focus on snow removal priorities as identified in Section 8-1-30(A).Some roads may be closed and traffic rerouted so snow removal vehicles can operate unimpeded by traffic.The on-duty Snow Boss shall refer to Section 8-1-30 of this Code. 3. Level 3: Snow Removal Operations shall focus on all roads. The effort and resources expended shall vary depending on accumulation and drifting conditions. The on-duty Snow Boss shall refer to Section 8-1-30 of this Code. PAGE 4 2023-3779 ORD2023-16 Sec.8-1-60.No waiver of governmental immunity. No term or condition set forth in this Article shall be construed or interpreted as a waiver, express or implied,of any of the immunities,rights,benefits,protections,or other provisions,of the Colorado Governmental Immunity Act,Section 24-10-101,et seq.,C.R.S.,as applicable. Furthermore,nothing set forth in this Article shall be construed as creating a duty of care upon any individual or party. Add Sec.8-1-70.No expectation of service to any specific person or property. The provisions stated in this Article are not intended to,nor shall they,create in any specific person or property a right to expect a certain level of service,even if such level of service is described herein. Amend ARTICLE II—Improvements Agreements Sec.8-2-10.Reserved. Sec.8-2-20.Improvements Agreements. Depending on the land use project, there are several different types of possible Improvements Agreements that may be required.It is the intent that Improvements Agreements will be in place prior to final approval of the use.Construction of any safety improvements are intended to be completed prior to operation or issuance of building permit(s). A. An Improvements Agreement reference may be used interchangeably and include but is not limited to immediate off-site and/or on-site improvements, future triggered improvements,and road maintenance criteria. (All categories may or may not include a proportional share based on locations and existing background traffic.) B. Agreement Types include: 1. Improvements Agreement(IA).This agreement is for projects that include future triggered improvements. Typically includes a standard road maintenance section for items such as dust suppressant or pavement damage repair. If applicable,will include a proportional share component for any future improvements done by the County on the haul or travel route. 2. Offsite Improvements Agreement(OFFSIA).These agreements include immediate off-site improvements.Immediate safety improvements may include but are not limited to,adding auxiliary lanes,intersection improvements,paving of gravel road, or widening of a road. These agreements will require project and warranty collateral and will also include all components described in the improvements' agreements. PAGE 5 2023-3779 ORD2023-16 3. On-Site Improvements Agreement(ONSIA).These agreements require immediate on-site improvements intended for public use but privately maintained,which may include but are not limited to, dedication of rights-of-way for public use, construction of an internal roadway,and/or construction of irrigation or stormwater ponds. 4. Road Maintenance Agreement(RMA). A Road Maintenance Agreement includes items addressing routine road maintenance, including but not limited to, dust suppressant if on a gravel road and pavement damage repair if on a paved road. There will also be a proportional share component for typical road maintenance improvements performed by the County specifically identified to the haul and travel routes related to the project. 5. Road Maintenance During Construction(RMCA).These agreements are similar to the Road Maintenance Agreement but are limited in time. Often used for transmissions lines,solar energy facilities and other land use projects where the heavy traffic impact on the roads is limited to the construction of the facility/use. These agreements will still include a proportional share component for routine road maintenance improvements performed by the County on the haul and travel routes related to the project. Pre and post construction inspections are required for these agreements. Sec.8-2-30.Collateral. A. Improvements Agreements requiring collateral as financial assurance that the obligations of the Agreement will be completed (including, but not limited to, Subdivision and Development Improvements Agreements for major and minor subdivisions and Development Improvements Agreements for Planned Unit Developments)shall generally conform to this Article II. B. The County requires applicants to provide acceptable collateral to guarantee all of their obligations under the associated Improvements Agreement in the following forms:(1) Project Collateral for completion of all improvements described in the Improvements Agreement;and(2)Warranty Collateral to ensure all public improvements uphold their functionality during the warranty period. C. All references to"Acceptance of Improvements"shall refer to the County confirming completion of the improvements according to the accepted Construction Plans. By accepting any improvement,the County does not thereby accept it for purposes of future maintenance, nor does the County accept any present or future responsibilities or obligations relative to the improvements. D. The Board of County Commissioners reserves the right to reject collateral that it deems inappropriate or insufficient. E. Release of collateral is the sole discretion of the Board. PAGE 6 2023-3779 ORD2023-16 Sec.8-2-40.Acceptable types of collateral. The three(3)types of collateral listed below are acceptable to the County: A. An irrevocable letter of credit from a federal-or state-licensed financial institution that has at least a three-star rating given by Bauer Financial consistent with a sample form supplied by the County.The Board may require the applicant to obtain replacement collateral if the rating of the financial institution providing the collateral drops below this level,which shall be submitted within sixty(60)days of the Board's notice to the applicant that the rating has fallen and that the collateral must be replaced.The applicant may not terminate existing collateral until replacement collateral has been secured. 1. The letter of credit shall provide for payment upon demand to the County if the applicant has not performed the obligations specified in the Improvements Agreement and the issuer has been notified of such default or if,after the County has received notice that the letter will not be renewed as set forth below,the County notifies the issuer that the applicant has not provided adequate replacement collateral and the County intends to demand payment,regardless of whether applicant is then in default. 2. The issuer of the letter of credit shall guarantee that,at all times,the unreleased portion of the letter of credit shall be available to the County for the purpose of completing the uncompleted improvements enumerated in the Improvements Agreement. 3. The letter of credit must stipulate that it will automatically renew and shall remain in full force and effect until released by action of the Board,or until after the Board has received a minimum of sixty(60)days'written notice from the issuer of the letter of credit of the pending expiration.The notice shall be sent by certified mail to the Clerk to the Board. B. A surety bond given by a corporate surety authorized to do business in the State and having at least a B+rating given by A.M.Best.The Board may require the applicant to obtain replacement collateral if the rating of the financial institution providing the collateral drops below this level,which shall be submitted within sixty(60)days of the Board's notice to the applicant that the rating has fallen and that the collateral must be replaced.The applicant may not terminate existing collateral until replacement collateral has been secured. C. A cash deposit made with the Board. Sec.8-2-50.Project Collateral. A. The value of Project Collateral submitted to the County must be equivalent to one hundred twenty-five percent(125%)of the value of the improvements identified on the accepted Construction Cost Estimate exhibit to the Improvements Agreement. PAGE 7 2023-3779 ORD2023-16 B. The Project Collateral shall be submitted with a signed Improvements Agreement including all required exhibits.The complete submittal is subject to final approval by the Board and shall be recorded at the Office of the Clerk and Recorder by the Clerk to the Board upon approval. C. Unless otherwise set forth in the Improvements Agreement Construction Schedule exhibit, the improvements shall be completed within three (3) years of execution of the Improvements Agreement.Otherwise,the Board,at its discretion,may make demand on all or a portion of the collateral and complete the improvements or partially complete the improvements,which may include,at the Board's discretion,contracting to have the work completed by a third party. D. Project Collateral may be provided separately for on-site and off-site Improvements. Sec.8-2-60.Release of Project Collateral. A. Upon completion of the improvements in accordance with the Improvements Agreement, the developer shall notify Weld County,so staff may inspect the improvements. B. Following preliminary approval by County staff,the developer shall present a Statement of Substantial Compliance signed and stamped by a Colorado Professional Engineer licensed to do business in the state and a request for release of collateral.The Statement of Substantial Compliance shall certify the work has been completed in substantial compliance with approved plans and specifications,or that any material deviations have received prior written acceptance from the County, and the engineer or his or her representative has made regular on-site inspections during the course of construction and the construction plans utilized are the same as those accepted by the County. C. "As-built"plans are required for all public improvements,which may include but are not limited to,public rights-of-way,permanent easements,or on-site drainage features.As- built"plans shall be stamped by a Colorado Professional Engineer licensed to do business in the state certifying the project is in substantial compliance with the plans and specifications and shall be submitted at the time the letter requesting release of collateral is submitted. D. For improvements to public rights-of-way or permanent easements,materials test results must be submitted for all phases of the project,as per the Colorado Department of Transportation (CDOT) Schedule for minimum materials sampling, testing, and inspections found in the CDOT Materials Manual. E. If applicable, a letter of acceptance of maintenance and responsibility identifying all improvements are in place and in accordance with the approved plans submitted from the appropriate utility company,fire,water,and/or other special district,and/or municipality for any utilities and improvements shall be submitted with the request for release of collateral. F. The written request for release of Project Collateral shall be accompanied by Warranty Collateral in accordance with Section 8-2-70,Warranty Collateral,below. PAGE 8 2023-3779 ORD2023-16 G. County staff shall schedule the request for consideration by the Board at a regularly scheduled public Board meeting and notify the applicant of the hearing date and time.The Project Collateral shall be released after final written acceptance by the Board. Sec.8-2-70.Warranty Collateral. A. Warranty Collateral shall be in an amount equal to fifteen percent(15%)of the value of the improvements as shown in the Improvements Agreement,excluding improvements fully accepted for maintenance by the responsible governmental entity,special district,or utility company. B. The warranty period shall be two(2)years from the date of the Board's consent to release the Project Collateral. Sec.8-2-80.Release of Warranty Collateral. A. Following the conclusion of the warranty period,the applicant shall submit a written request for release of the Warranty Collateral to Weld County. B. County staff shall inspect the improvements. If the improvements need mitigation or repairs are required,said work must be completed prior to release of the Warranty Collateral.In the event an applicant fails to adequately repair improvements associated with the Improvements Agreement,the County shall have the authority to pursue,at its sole discretion,Warranty Collateral to the extent necessary to complete the repairs in order to preserve public interest. C. If no improvements require mitigation or repairs,County staff shall schedule the request for consideration by the Board at a regularly scheduled public Board meeting and notify the applicant of the hearing date and time.The Warranty Collateral shall be released after final written acceptance by the Board. Sec.8-2-90.Proportional Share Process for Improvements Agreements. A. The proportional share process is an important tool used by the County to identify the shared cost of safety improvements for existing and new development to mitigate impacts to the county road system. B. Weld County uses the Equivalent Single Axle Load(ESAL)methodology when calculating an Improvements Agreement proportional share.The ESAL methodology is a national standard for normalizing traffic counts to reflect the actual damage caused by large vehicles.The purpose of the methodology is to create the most reasonable and fair method for analyzing traffic data and the impacts to county infrastructure. C. Weld County maintains a current list of approved and recorded Improvements Agreements. Annually,the Improvements Agreement haul,or travel routes are evaluated to determine which roads will have proportional share costs for Weld County identified projects the next calendar year and therefore,what owners/land use permits will be affected so they can be notified in advance. PAGE 9 2023-3779 ORD2023-16 D. Once the Improvements Agreement permit holders are identified,Development Review sends a courtesy letter notifying them of the anticipated proportional share associated with their use.This letter is meant to be general in nature and will not contain specific costs or percentages associated with the required contributions. It is meant to give permit holders preliminary notice that a project will be occurring in the upcoming calendar year. E. On or before December 31 of the year prior to the Weld County identified projects,the permit holder will receive another letter giving the proportional share percentage with supporting documentation.An estimated cost will also be provided at this time. F. Permit holder shall have the opportunity to review supporting documentation,review, comment and supplement the County's data,collection methodology and determinations. If the project is completed by the Public Works Department,the proportional share will be based on materials only.If the work is completed by a private contractor,the cost will be based on both materials and labor. G. The final cost will be based on actual costs of the work performed and will be invoiced to the permit holder at the completion of the project. H. The County's criteria for calculating the ESAL proportional share is identified in Appendix 8-Q. ARTICLE III-Culverts Add Sec.8-3-10.Purpose. For the purpose of this Article,culverts may refer to, road culverts,driveway/access culverts,cross culverts,irrigation culverts,and similar structures that convey and maintain the natural flow of water carried in the roadside ditches. Amend Sec.8-3-20.Installation of access culvert. A. The property owner shall pay the costs for materials for new road access culverts whenever the installation of a culvert is made necessary by the creation of a new access from private property to a County road,by any alteration of the natural flow of water across private property by the owner,or for any other reason created by any owner of private property.The culvert shall be installed according to Appendix 8-Q of the Weld County Engineering and Construction Criteria as to size and location in the County rights-of-way or other County property in which such culverts may be installed.Consideration of culvert sizing shall be based on the existing upstream and downstream culvert diameter size.The culvert size will be determined in accordance with standard engineering practices by Public Works Operations at the time of culvert installation.The property owner shall be responsible for cleaning the borrow or roadside ditch to the extent required to accommodate the road access culvert and ensure proper drainage. B. Property owner/user shall submit a Culvert Installation Form to Public Works for invoicing of the materials of the culvert installation.Property owner/user shall provide payment prior to culvert installation.The application form is available at Public Works. PAGE 10 2023-3779 ORD2023-16 Amend Sec.8-3-30.Maintenance. After county acceptance of the culvert installation,Weld County shall be responsible for the maintenance and repair of the road access and/or any related culvert.In the event of an emergency or if a hazardous situation is observed or detected,the property owner shall be notified and requested to provide an immediate remedy to the situation.If the property owner fails to react, the County shall correct the hazardous situation and may bill the property owner for all incurred expenses. Add Sec.8-3-40.Maintenance of irrigation structures. The County's duty to maintain culverts,bridges or similar structures used for irrigation purposes shall be in accordance with the following statutory requirements: A. Section 43-5-305(1),C.R.S.,which states as follows: "Any person or corporation owning or constructing any ditch,race,drain,or flume in,upon, or across any highway shall keep the highway open for safe and convenient travel by constructing culverts,bridges,or similar structures over such ditch,race,drain,or flume. When any ditch is constructed across,in,or upon any highway,the person owning or constructing such ditch shall construct a culvert,bridge,or similar structure long enough to conduct the water from shoulder to shoulder from such road or highway or of such greater length as the Board of County Commissioners having jurisdiction thereover may require,plans for the culvert,bridge,or similar structure having been approved in advance by the Board of County Commissioners.The Board of County Commissioners shall maintain the culvert,bridge,or similar structure after construction,in accordance with the provisions of Section 37-84-106,C.R.S." B. Section 37-84-106,C.R.S.,which states as follows: "All bridges constructed over any ditch,race,drain,or flume,crossing any public highway, street,or alley,after construction,shall be maintained by and at the expense of the county or municipality in which the ditch,race,drain,or flume may be situated." C. In the event of an emergency or if a hazardous situation is observed or detected,the County shall notify the property owners/users to request the irrigation water be shut off in conjunction with property owners/users schedule,in order to perform emergency repairs. If Public Works identifies this road as an essential travel or haul route,or inadequate detour route availability and the property owner/users fails to react,the County shall correct the hazardous situation and may bill the property owner/user for any incurred expenses. Amend Sec.8-3-50.County Authority. Remainder of Section—No change. PAGE 11 2023-3779 ORD2023-16 ARTICLE IV-Use of Borrow or Roadside Ditches Add Sec.8-4-10.Purpose. Borrow or roadside ditches are intended to intercept surface water from agricultural fields or residential property.Roadside ditches are not intended to accommodate forced point source discharges.Tailwater ditches are not recognized as part of Weld County's conveyance system. Amend Sec.8-4-20.Responsibilities. Whenever possible,the county shall try to separate agricultural farming operations out of the county road right-of-way, especially when located in a municipal separate storm sewer systems(MS4)area.Persons in the County who are currently using borrow/roadside ditches along County rights-of-way for agriculture uses,whether the consent to such uses was originally given expressly or implied,must adhere to the following conditions: A.thru C.—No change. D. Tailwater shall be controlled to prevent erosion and sedimentation of the borrow ditches. Add Sec.8-4-30.Maintenance. A. Public works prioritizes and maintains Roadside Ditches on a case-by-case basis,as needed,to remove sediment,debris,trash,or other encumbrance that may be impeding the proper flow of water.Landowner's or tenant's may contact Public Works to request an inspection of a Roadside Ditch.Public Works personnel will inspect and schedule the Roadside Ditch to be cleaned,if deemed necessary.In the event drainage water overflows a Roadside Ditch,Public Works personnel will inspect the Roadside Ditch and determine if action,such as ditch cleaning,is required or if the event produced excessive runoff beyond the capacity of the drainage system. B. Roadside ditches are intended to carry stormwater from county roads to natural drainage basins.The amount of stormwater a roadside ditch carries varies.For planning purposes, Weld County never assumes a roadside ditch can carry more water than five(5)cubic feet per second(cfs). C. Nonexclusive License Agreements(NELA's)for private irrigation structures located in county rights-of-way shall be done by separate Agreement on a case-by-case basis where the Board grants a nonexclusive license to access,construct,operate,and/or maintain privately owned equipment within county road right-of-way/property. Amend Sec.8-4-40.Violations. If the Board of County Commissioners determines that users are violating the above- stated conditions,the Board may consider the revocation of its prior consent,whether express or implied. The revocation of consent may be entered by resolution of the Board of County Commissioners,following notice to the owner and user(if the user can be determined),and a hearing held pursuant to the procedures for adjudicatory type hearings.The Director of Public PAGE 12 2023-3779 ORD2023-16 Works shall have the burden of showing,by a preponderance of evidence,that the owner and user have failed to comply with Section 8-4-20 herein. ARTICLE V-Cattle Guards Amend Sec.8-5-10.Purpose. Person includes any individual,business or corporation,who is not a landowner,must demonstrate authority to act on behalf of the landowner prior to coordination with the county on the installation of cattle guards.Cattle guards are intended to restrict the movements of livestock and are not intended to be used for drainage and utility purposes. Amend Sec.8-5-20.New installations/Relocation. Any person in the County who wishes to install a cattle guard on any County road may do so only upon the following conditions: A. Property owner/User shall submit a Cattle Guard Installation/Relocation Form to Public Works for invoicing of the cost of the materials of the Cattle Guard installation/relocation. Property owner/User shall provide payment prior to Cattle Guard installation/relocation. The application form is available at Public Works. B. The entire cost of installation or relocation of a cattle guard is paid by the person making the request,with the County doing the installation/relocation,or by requester with the County's written approval.Weld County will be responsible for maintenance and cleaning of Cattle Guards after installation is completed. C. The Department of Public Works shall be notified prior to installation/relocation of a cattle guard.An invoice will be sent and payment received in accordance with the written agreement form attached in Appendix 8-C of this Chapter,the Department of Public Works must receive the form at least thirty(30)days prior to the date of the installation/relocation. D. The agreement between the Department of Public Works and the person making the request,detailing the rights and obligations concerning the cost of the Cattle Guard shall be signed by the person making the application.Maintenance and repair of the cattle guards,shall be Weld County responsibility. E. Any cattle guard which is installed in County road rights-of-way must comply with any and all standards required by the Department of Public Works,including but not limited to,the County's Specifications for Cattle Guard Installation. Amend Sec.8-5-30.Maintenance. A. Any person who benefits from any cattle guard located upon any maintained County road has the responsibility to periodically inspect for maintenance,proper function and inspect for cleaning.The person must notify Public Works within the same five(5)working days in which the person obtains the knowledge of the need for maintenance. PAGE 13 2023-3779 ORD2023-16 Cattle guard maintenance includes but is not limited to,the removal of all sand,dirt,silt and other solid debris which renders the cattle guard ineffective.The county deems a cattle guard-cleaned when the space within the cement box and below the grate of the cattle guard are free of debris. Cattle Guard maintenance requests may be completed by the County within thirty(30) days of the request. B. The maintenance of any cattle guard on any maintained County road shall be the responsibility of the County. C. In the event a Cattle Guard is deemed,by the County,to be beyond maintenance or repair, the County shall replace the cattle guard at the county's expense. Delete Sec.8-5-40.Reserved. Delete Sec.8-5-50.Reserved. Delete Sec.8-5-60.Reserved. Amend Sec.8-5-70.Vested right. No portion of these policies shall be considered to have vested any person with the right to a particular size of cattle guard.The County,upon a determination that road improvement or widening is necessary, may require replacement of existing cattle guards. The county is responsible for Cattle Guard costs. ARTICLE VI-Miscellaneous Provisions Amend Sec.8-6-10.Gravel pits. The County shall obtain all required state and federal permits for Public Works operations. A. Gravel obtained from County permitted gravel sites shall not be sold or used for other than governmental purposes, except by specific authorization of the Board of County Commissioners. B. The County will acquire,in its name,all gravel mining permits for gravel mining on County- owned property.When the property is not owned by the County,the issue of the obligation to obtain,maintain and pay the costs of permits shall be addressed contractually. Delete Sec.8-6-20.Reserved. Delete Sec.8-6-30.Reserved. Delete Sec.8-6-60.Reserved. PAGE 14 2023-3779 ORD2023-16 Amend Sec.8-6-70.Satellite Facility use. Gravel Road operators may park personal vehicles in satellite facilities while performing road maintenance work for the County. Any personal use of satellite facilities by County employees or any other individual except as specified above is prohibited. Amend Sec.8-6-80.Satellite Facilities utilities and rents. When the County owns the satellite facility and a trailer pad,that item associated with the satellite facility will be provided at no cost.Other than as specifically stated herein,utilities of gas and electricity shall not be provided to any grader operator in the County.Each operator will be responsible for his or her own gas and electricity. Amend Sec.8-6-100.Gravel road fugitive particulate emissions policy and procedure. A. General. Growth throughout the County has led to increased vehicular traffic on all roadways under the County's jurisdiction,as a result a fugitive dust application may also be required for detour routes,or any other reason deemed appropriate by Public Works. B. Fugitive dust applications may be required if increased traffic on unpaved County roads has resulted in dissatisfaction with the levels of fugitive particulate emissions caused by vehicles traveling those roadways.The County must also make reasonable efforts within budgetary constraints to comply with regulations established by the State Air Quality Control Commission regarding this issue.In an effort to reasonably comply with air quality regulations,the policies and/or procedures set forth in this Section will be adhered to when considering requests for fugitive dust abatement. C. Responsibility for fugitive dust.The County-maintained roadway segments with Annual Average Daily Traffic(AADT)volumes exceeding two hundred(200)vehicles per day should be treated to inhibit fugitive dust at the expense of the County subject to available budgetary appropriations.The process for the determination of qualifying AADT volumes will be as outlined in Subsection D below.Roadway segments with AADT volumes below two hundred(200)vehicles per day may also be treated for fugitive dust at the expense of property owners in accordance with Subsection F of this Section. D. Procedures for determination of traffic volumes in conjunction with fugitive dust issues. 1. Routine counts. Traffic counts will be taken as needed on gravel roadway segments in areas of the County which are determined by the County to have significant growth trends. 2.—No change. 3. Traffic count procedure.If the AADT count exceeds two hundred(200)vehicles per day,the roadway segment will be recounted in ninety(90)calendar days using the methods noted above to confirm the original count.If this count is significantly below the two hundred(200)vehicles per day AADT,the roadway may not be treated by the County for fugitive dust control.When the County determines the PAGE 15 2023-3779 ORD2023-16 use of weekend or partial weekend counts could assist in establishing a representative average daily traffic count when factored with weekday counts,the seventy-two-hour count may include those time periods. D. Determination of fugitive dust control mitigation.When a roadway segment meets the criteria for County mitigation, the County may,when practical and within budgetary constraints,select one(1)of the following alternatives to mitigate fugitive dust: 1.—No change. 2. Full depth treatment using dust control agents using no more than two(2) applications per year at the County's discretion. 3. Recycled asphalt treatment up to eight-inches(8")and may also include a dust control agent,per Public Works discretion. 4. Asphalt or concrete paving, based upon qualification though the Capital Improvement Project prioritization process. 5. Speed limit reductions. Delete 5.Periodic watering. The mitigation alternative and time of implementation will be based on budget and seasonal constraints.The County will confirm the need for continued mitigation on roadway segments by conducting traffic counts using the procedures noted above and maintaining historical traffic count records.Should the AADT on a road segment fall below two hundred(200) vehicles per day,dust control mitigation may be discontinued by Public Works. E. Private application.The County has no objection to individuals applying dust control chemicals to County roads at their own expense,provided that they agree to the following conditions: 1.—No change. 2. Private application shall not include used oil applications. 3. Dust control chemicals must be applied in such a manner that will not contaminate any roadside ditches.Therefore,any materials which may wash from the roadbed will not be suitable. 4.—No change. 5. All dust control agents used on County roads shall be approved for use by the Department of Public Works. 6.—No change. PAGE 16 2023-3779 ORD2023-16 7. All private application must be applied by a Weld County approved vendor,who must obtain a county right-of-way use permit. Amend Sec.8-6-110.Survey monuments. A.—No change. B. In order to avoid having surveyors dig holes in paved road intersections to locate the monuments,the monument should be enclosed in a box which is kept at least one-quarter inch(1/4")below the roadway surface. 1.thru 5.—No change. C. For gravel roads,the monument shall be located at least one(1)foot below the roadway surface. D. On concrete paved roadways the monuments shall be surface mount type CDOT class section 629,type 5(Brass)and shall be recessed 1/2"below the surface. Amend Sec.8-6-130.Trees in rights-of-way. A.—No change. B. It is the policy of the County that when trees on private property begin to obstruct visibility on County roads,the property owner shall be given notice to trim the trees within a reasonable time. Remainder of section—No change. Delete Sec.8-6-140.Reserved. Sec.8-6-150.Road maintenance acceptance policy for public roads. Persons desiring to obtain County maintenance of public roads shall first address such request to the Board of County Commissioners for its consideration at one(1)of its regularly- scheduled business meetings.The person making the request shall be responsible to pay the entire cost of notification to owners and/or occupants of lands lying adjacent to the roadway.Such notification shall include a description of the request and shall set forth the time and place of the Board consideration. County maintenance of public roads may occur only if authorized by resolution of the Board of County Commissioners.Before a public road may be authorized by the Board for maintenance,the road must meet the following minimum conditions: A.and B.—No change. C. The width of the road right-of-way shall not be less than sixty(60)feet. D. The road shall serve a minimum of five(5)legal lots,which must be developed with residential, commercial or industrial improvements to be considered for acceptance. PAGE 17 2023-3779 ORD2023-16 Properties abutting the intersection of the road under consideration for acceptance and an existing publicly maintained road do not count toward the required five(5)lots. E. Any new road width shall be a minimum of twenty-six(26)feet of graveled surface or meet the minimum design guidelines for the anticipated traffic on the roadway segment being considered. F. The following shall be the minimum acceptable standards before a road is accepted for maintenance: 1.—No change. 2. Borrow ditches shall be a minimum of twenty-four(24)inches deep with 4:1 side slopes and graded to provide adequate drainage on a case by case basis. 3. All driveway side road borrow ditches shall be sufficient to carry the five-year storm or be a minimum of an fifteen-inch-diameter culvert or culvert size based on the upstream and downstream culvert size as determined by the Director of Public Works.Crossroad drainage structures shall be sufficient to carry the ten-year storm or be a minimum of a fifteen-inch culvert as determined by the Director of Public Works. 4. The Department of Public Works shall test and inspect the roadbed subgrade for structural adequacy and acceptable materials,in accordance with the most current versions of the CDOT Field Materials Manual,reference CP 23,and the Standard Specifications Book SECTION 203 EXCAVATION AND EMBANKMENT. 5. A minimum of four(4)inches of compacted surface gravel in accordance with Table 9-12 of the Weld County Engineering&Construction Criteria found in Appendix 8-Q. G. There shall be no fences or other obstructions within county road right-of-way.If cattle have cross-access to the roadway,a cattle guard shall be installed in accordance with Article V above. H. If a fence exists along the section line on which the road is to be built,relocation of the fence to the county road right-of-way lines shall be the responsibility of the sponsor(s)of the roadway project. I. Reimbursement by the persons requesting authorization of County maintenance of public roads shall be made for acreage within the county road right-of-way included in an adjacent property Conservation Reserve Program (CRP) crop or which has an unharvested annual crop demolished by the roadway construction project. Remainder of section—No change. PAGE 18 2023-3779 ORD2023-16 Amend Sec.8-6-170.Obstructions within county rights-of-way. The County reserves the right to maintain its road rights-of-way without obstructions located thereon. Obstructions include, but are not limited to, fences, trash cans, gates, landscaping materials,irrigation structures,and any structure that does not meet the intent of being constructed with breakaway materials,regardless of whether or not they are physically located on the traveled portion.Obstructions shall be removed from the County road rights-of- way upon request by the Department of Public Works.The total expense of the removal of any obstruction from a County road right-of-way will be paid by the person who installed the obstruction,or by the person exercising ownership or control over the obstruction.In the event such person does not remove the obstruction as requested, the County will remove the obstruction and bill the person responsible for the obstruction for any expenses incurred in its removal.This Section shall not alter any rights,responsibilities and/or penalties regarding the act of obstructing highways as set forth in Sections 18-9-107 and 43-5-301,C.R.S. Delete Sec.8-6-180.Reserved. Amend ARTICLE VII-Signs and Pavement Markings Sec.8-7-10.Purpose. The County's roads require certain pavement markings and signs per the Manual on Uniform Traffic Control Devices,and Colorado state statute. The pavement markings and signs are to serve the public interest in traffic safety. Sec.8-7-20.Sign policy. A. The County sign shop shall produce signs for County-maintained roads in subdivisions, unincorporated areas and historic townsites;where the signs are produced pursuant to a separate intergovernmental agreement with a governmental agency;and for non-County- maintained roads upon request and payment of the cost of the(blue)signs by the persons making such requests. B. All signs placed in the County rights-of-way must conform to the Manual on Uniform Traffic Control Devices(MUTCD). No signs, except those installed by the County, shall be located within County rights-of-way and all signs adjacent to rights-of-way must meet applicable building and zoning codes. Sec.8-7-30.Memorial signs. A. The memorial sign must be requested by the victim's family or other sponsor with the consent of the victim's family through an application. Upon submittal of a Roadside Memorial Sign Application with fee to the Department of Public Works,the County shall review application for acceptance.The application form is available at Public Works. 1. If accepted,the Department of Public Works shall construct,install,and maintain the requested roadside memorial sign for four (4) years after the date of installation. After four(4)years,the sign shall be removed and held for a period PAGE 19 2023-3779 ORD2023-16 of thirty(30)days to provide the applicant the opportunity to pick up the removed sign for keeping. Signs not claimed within the thirty(30)day period will be recycled. 2. If the application is not accepted by the County,the fee shall be returned to the applicant. No private installation or maintenance of roadside memorial signs is allowed. B. These memorial signs shall consist of two(2)sign panels measuring standard dimensions in accordance with the MUTCD. 1. There are four(4)alternative messages for the top sign panel. These messages correspond with the type of accident or situations that occurred during the accident. The four(4)messages are: a. "Please Drive Safely"—this is the most common message used for these signs. b. "Please Ride Safely"—this message is for accidents involving motorcycles or bicycles. c. "Please Buckle Up"—this message is for accidents involving victims who were not wearing their safety restraints. d. "Don't Drink and Drive" —this message may only be used for fatal alcohol/drug(DUI)related accidents where there has been a conviction of the driver involved in the fatal crash who was in violation of Colorado DUI laws, or a toxicology report showing the victim driver to have been in violation of Colorado's DUI laws. 2. The bottom sign panel will include the message"In Memory or and the victim's name as shown in the application. The bottom sign panel can show multiple names if there were multiple victims in the accident and each of those victims' immediate family gives permission for the names to be added in the application. C. Memorial signs shall only be installed by the County on County-maintained rights-of-way. The Department of Public Works shall install the sign as close as possible to the location given in the application.If that location conflicts with existing signs or creates an unsafe condition,the sign will be moved to where it can be installed safely.If the roadway is annexed by a local municipality after installation,the applicant will be required to receive permission from that municipality for the sign to remain;otherwise,the County will remove the sign if requested by the annexing agency and return it to the applicant. Removed signs shall be held for a period of 30 days to provide the applicant the opportunity to pick up the removed sign for keeping. Signs not claimed within the thirty(30)day period will be recycled. D. The applicant shall submit a fee,as determined by the Board of County Commissioners, to help cover the sign's material cost, installation,maintenance, and removal by the PAGE 20 2023-3779 ORD2023-16 County.In a multiple-fatality crash,the fee may be split equally between those families who want their family members'names on the sign.Once removed,each separate family may receive a sign to keep if requested. Removed signs shall be held for a period of 30 days to provide the applicant the opportunity to pick up the removed sign for keeping. Signs not claimed within the thirty(30)day period will be recycled. E. This section is considered to be the County's permitting system for roadside memorial signs and is in lieu of the procedural requirements of Section 43-2-149,C.R.S. ARTICLE VIII-Transportation Planning Add Sec.8-8-10.General. Transportation planning for Weld County is a continuing,cooperative,and comprehensive process that includes the development of planning documents,working with regional agencies, securing funding for transportation projects,and reviewing safety data.Weld County collaborates with many different regional agencies in order to plan and implement needed improvements to the transportation system. Planning of the roadway network with respect to functional classification,alignment,and intersection/access spacing is developed through transportation planning.Weld County will continue to build and maintain a safe and reliable transportation system through prudent transportation planning. Add Sec.8-8-20.Purpose. The purpose of this Article is to identify transportation planning policies,as well as the guiding technical documents for Weld County for the basis of formulating transportation planning related policies. Amend Sec.8-8-30.Weld County Transportation Plan and Functional Classification Map. A. The Weld County Transportation Plan,as amended("Transportation Plan"),is intended to summarize existing transportation conditions,recommend policy,funding and roadway development for the County over a twenty-five-year planning horizon.The Transportation Plan will serve an integral part in the decision-making process for County staff and elected officials.The Transportation Plan will also be an extension of the Comprehensive Plan focusing on basic travel characteristics unique to the County.The Transportation Plan is found in Appendix 8-N of this Chapter and is intended to be used in concert with Chapter 22 of this Code.It is recommended to update this plan when updating the Comprehensive Plan. B. The Functional Classification Map is a component of the Transportation Plan and is the process by which County roads are grouped into classes according to the character of service provided.Grouping the roads into classes identifies the required minimum width of future road right-of-way and locations for future road right-of-way reservation.The Transportation Plan recommends the Functional Classification Map be reviewed every two to three years,and can be amended by the Board of County Commissioners,as needed.A link to the Functional Classification Map is found in Appendix 8-O of this Chapter. PAGE 21 2023-3779 ORD2023-16 C. The minimum road right-of-way widths are as follows,unless shown otherwise on the Functional Classification Map found in Appendix 8-O of this Chapter: 1. Arterial: 140 feet. Arterials may include planned roundabouts or other traffic features that necessitate expanded road right-of-way width as shown in arterial studies adopted by the Board of County Commissioners by resolution. 2. Collector:80 feet. 3. Local:60 feet.All roads maintained by Weld County have a minimum of 60 feet of road right-of-way. 4. Minimum road right-of-way widths for"Arterials Not Constructed"shown on the Functional Classification Map are found in project identifications and/or designs approved by resolutions of the Board of County Commissioners by resolution. 5. Minimum road right-of-way widths for Weld County four-lane controlled-access highways detailed in C.R.S. Section 43-2-110 are identified in approval documents. D. Where road right-of-way has not been dedicated or otherwise acquired by the County,but the County maintains a public road,the width of the prescriptive road right-of-way,which includes the entire area necessary for maintenance by the County,shall be a minimum of 60 feet(30 feet from either side of the center of the road). E. Weld County identifies primary and secondary roadway classifications,as required by C.R.S.§43-2-101.Each year,the Weld County Department of Public Works submits a map to CDOT showing the Weld County Primary and Secondary Road System and the total miles of public roads maintained by Weld County and eligible for participation in the HUTF,pursuant to the requirements of C.R.S.§43-2-110(1). Delete Sec.8-8-40.Reserved. ARTICLE IX-Municipal Separate Storm Sewer System Amend Sec.8-9-50.Definitions. For the purpose of this Article,the following terms,phrases,words and their derivations shall have the meanings given herein: Construction dewatering permit means the Colorado Discharge Permitting System (CDPS)General Permit COG080000,Construction Dewatering Discharges,which is regulated by the Colorado Department of Public Health and Environment,Water Quality Control Division. Add Development area means the area of land disturbance,including past and future phasing. When multiple lots are involved,such as a subdivision of land,the potential cumulative land disturbance will be considered the development area for the purposes of drainage design. PAGE 22 2023-3779 ORD2023-16 Stormwater means any surface flow,runoff and drainage occurring during or following any form of natural precipitation event and resulting therefrom and consisting entirely of water from natural precipitation events including snowmelt. Remainder of section—No change. Amend Sec.8-9-80.Pre-construction. A.—No change. B. Pre-construction requirements.The following documents are required to be submitted and accepted by the Department of Public Works prior to any land-disturbing activity that will disturb greater than or equal to one acre of land.Applicable land-disturbing activity includes the total disturbed area,either planned or potential,from a common plan of development or sale.The Department of Public Works shall determine applicable sites and required documentation necessary to comply with MS4 Permit requirements. 1.thru 4.b.—No change. c. Drainage report; identifying the following components: site drainage; design details for permanent control measures; narratives for non- structural control measures,if applicable;and corresponding calculations used in determining compliance with the"Base Design Standards"of the MS4 permit. "Base Design Standards"are detailed in the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q,Sec.6.2.6.2—Permanent Water Quality Control Measure Design). d.thru f.—No change. C. Enforcement. Failure to comply with this Section is a violation of this Article and enforcement procedures shall be pursued as detailed in Section 8-9-130.Additionally,a `hold'may be placed on the applicable parcel(s),which prevents future permitting of the site until requirements are met. Amend Sec.8-9-90.Construction activity. A.thru B.2.b.—No change. Delete c. Indicator inspection: c. Inactive site inspection:An inactive site inspection is conducted at least every ninety(90)days. Inactive site inspections are reserved for sites pending final stabilization,and all construction activity has been completed. PAGE 23 2023-3779 ORD2023-16 Detailed inspection procedures can be found in the Weld County Engineering and Construction Criteria Manual (Appendix 8-Q, Sec. 6.2.5.1 — Stormwater Inspections). C.—No change. D. Enforcement. Failure to comply with this Section is a violation of this Article and enforcement procedures shall be pursued as detailed in Section 8-9-130.Additionally,a `hold'may be placed on the applicable parcel(s),which prevents future permitting of the site until requirements are met. Amend Sec.8-9-100.Post-construction. A. Purpose.The purpose of this Section is to require the implementation and maintenance of permanent control measures to ensure post-construction requirements of the MS4 permit are met. All control measures shall be selected, installed, implemented and maintained in accordance with good engineering, hydrologic and pollution control practices.This Section applies to all land-disturbing activities commencing after July 1, 2019. B. Post-construction requirements.The following requirements are applicable to sites for which construction activity will create a disturbed area greater than or equal to one acre and sites which will have a cumulative disturbed area greater than or equal to one acre during future phasing.The requirements are applicable to individual sites as well as sites that are part of a larger common plan of development or sale. For subdivisions,the potential development area will be considered unless otherwise platted.The Department of Public Works shall determine applicable sites and required procedures and documentation necessary to comply with MS4 permit requirements. 1. Permanent control measures. a.—No change. b. "Base design standards"can be found in the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q, Sec.6.2.6.2-Permanent Water Quality Control Measure Design). c.—No change. 2. As-built submittal. a. After construction of drainage is complete, a certified as-built drawing, signed and stamped by a Professional Surveyor and licensed Professional Engineer in the State of Colorado,shall be submitted to the Department of Public Works. 3. Final inspection and acceptance. PAGE 24 2023-3779 ORD2023-16 a. After receiving the as-built,the County shall inspect the site to verify compliance with the Drainage Report,Drainage and Access Easements, Long-Term Operation and Maintenance Plan, and other submitted documentation.If the Department of Public Works determines the site has met the requirements of this Section,the site will be allowed to obtain a Certificate of Occupancy(CO).Otherwise,the parcel will remain on hold until all requirements have been met. 4. Post-acceptance oversight. a. Inspections of permanent control measures. Inspections shall be conducted at least every five (5) years, or an alternative frequency determined by the Department of Public Works,to ensure adequate long- term operation and maintenance of permanent control measures. The County Inspector shall verify the permanent control measure with the as-built and long-term operation and maintenance plan.If the inspector is unable to visually verify adequate functioning and maintenance of the permanent control measure,additional requirements may apply.Additional requirements may be avoided by installing structural components,such as a concrete trickle channel,which allows visual verification of adequate functioning and maintenance. 4.b.thru 5.—No change. C. Exemptions. 1.—No change. 2. A list of allowable exemptions under the MS4 permit can be found in the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q,Sec.6.2.6.1 —Exemptions).The most common exemptions are as follows: a. Large-Lot Single-Family Sites:A single-family residential lot,or agricultural zoned lands,greater than or equal to 2.5 acres in size per dwelling and having a total lot impervious area of less than 10 percent.A total lot imperviousness greater than 10 percent may be allowed when a study specific to the watershed demonstrates the expected soil and vegetation conditions are suitable for infiltration/filtration of the WQCV for the site. The maximum total lot impervious covered under this exclusion shall be 20 percent. b. Undeveloped Land:Sites with land disturbance to undeveloped land(land with no human-made structures such as buildings or pavement)that will remain undeveloped. c. Above Ground and Underground Utilities: Activities for installation or maintenance of underground utilities or infrastructure that does not permanently alter the terrain,ground cover,or drainage patterns from those PAGE 25 2023-3779 ORD2023-16 present prior to the construction activity.This exclusion includes,but is not limited to,activities to install,replace,or maintain utilities under roadways or other paved areas that return the surface to the same condition. D. Enforcement. 1. Failure to comply with this Section is a violation of this Article and enforcement procedures shall be pursued as detailed in Section 8-9-130. Additionally, noncompliance may result in an`MS4 hold'and may be placed on the applicable parcel(s), which prevents future permitting of the site until the parcel(s) requirements are met. Amend Sec.8-9-130.Enforcement procedures. A.—No change. B. Informal notice of violation.Except where a threatened discharge exists and/or emergency suspension is necessary,the Department of Public Works shall attempt to provide an initial informal notice to a person violating this Article.Such notice shall specify the location,type and severity of the violation and request that such person take immediate action to address the violation. Notices of violation are followed by compliance inspections to ensure the violation has been resolved.Failure to correct the violation within the specified time may result in a formal notice of violation. In the event reasonable efforts to communicate the informal notice to such person are unsuccessful,a formal notice of the violation shall be issued by the Department of Public Works. Causes for informal notices of violation include,but are not limited to: 1. Minor issues of improper handling,storage or disposal of potential stormwater pollutants; 2.and 3.—No change. C. Formal notice of violation.If the violation for which informal notice was given has not been resolved within fourteen(14)days of such notice,and no plan for corrective action has been communicated, and except where emergency suspension is necessary, the Department of Public Works shall provide a formal notice of violation to persons violating this Article.Formal notices of violation are also issued for recurring violations and/or violations more severe in nature. Notices of violations are followed by compliance inspections to ensure the violation has been resolved.Recurring violations may result in fees being assessed in accordance with Section 8-9-140 and/or enforcement methods being pursued in accordance with Section 8-9-150. Causes for formal notices of violation include,but are not limited to: 1.thru 9.—No change. Such notice shall describe the nature of the violation and may require without limitation: PAGE 26 2023-3779 ORD2023-16 1.thru 4.—No change. If abatement of a violation and/or restoration of affected property are required,the notice shall set forth a reasonable deadline within which such remediation and/or restoration must be completed. The written notice of violation shall be served by email or hand delivery or by certified mail,return receipt requested. Remainder of section—No change. ARTICLE XI-Storm Drainage Criteria Division 1-General Provisions Amend Sec.8-11-10.Intent. A. The intent of the chapter is to provide minimum standards to preserve and protect the public health,safety and general welfare in the unincorporated lands of the County, pursuant to authority granted by Part 4 of Article 15 of Title 30,and Article 35 of Title 30, C.R.S. Remainder of section—No change. Amend Sec.8-11-20.Definitions. For the purpose of this article, the following terms, phrases, and words and their derivations shall have the meanings given herein: Retention pond/Stormwater Infiltration facility: A flood control feature designed to temporarily store stormwater runoff and reduce peak flows.Retention ponds return water to the watershed through infiltration into the ground. Remainder of section—No change. Amend Sec.8-11-30.Adoption of storm drainage standards. A. The Mile High Flood District's"Urban Storm Drainage Criteria Manual,"(MHFD Manual) consisting of Volume 1,Volume 2,and Volume 3,as currently published or hereafter amended,is hereby adopted by reference,with the amendments and additions which are set forth herein.All references to"District"or"The District"within the MHFD Manual shall be replaced with"Weld County".All facilities for stormwater management on properties located within the unincorporated lands of the County,whether public or private,shall be designed and constructed in accordance with such criteria,unless a master drainage plan specific to the area of the site has been approved by the County. B. The criteria and procedures contained in this article are intended to supplement the MHFD Manual in ways specific to Weld County.In the case of a conflict between the MHFD Manual and the supplemental criteria and procedures in this article,such supplemental criteria and procedures shall take precedence over the MHFD Manual. PAGE 27 2023-3779 ORD2023-16 C. Further guidance for stormwater design and construction shall be in accordance with Chapter 5 of the Weld County Engineering and Construction Criteria. Amend Sec.8-11-40.Drainage policy. A.—No change. B. For new development,un-detained discharges to roadside ditches located in the County road right-of-way are prohibited. C.and D.—No change. E. Weld County shall review and approve new development in accordance with the storm drainage criteria of this article. F.—No change. G. Irrigation ditches shall not be used as outfall points for stormwater runoff from Uses by Special Review, Site Plan Reviews, Subdivisions, Planned Unit Developments, or WOGLAs unless such use is approved,in writing,by the ditch owner(s).Water quality treatment may be required. H. An as-built survey of stormwater facilities shall be provided if requested by Weld County. Add Sec.8-11-45.Exceptions. A. Exception criteria.Exceptions to stormwater detention shall not jeopardize the public health,safety,and welfare of public and private property.No stormwater detention will be required for sites that meet any of the following conditions.Requirements of the Municipal Separate Storm Sewer System(MS4)areas remain applicable.Weld County will confirm if the development qualifies for an exception based upon the information provided by the applicant.Exception requests shall be supported with an approved drainage narrative, which must describe the following minimum criteria: 1. The exception being requested for consideration. 2. Any existing and proposed improvements to the property. 3.thru 8.—No change. B. Exceptions. Uses that can be excepted from stormwater detention are limited to the following: 1.thru 5.—No change. 6. Gravel pits if the stormwater drains into the gravel pit.Releases from the site shall comply with the Weld County Engineering and Construction Criteria, including dewatering.Topographical information shall be provided. PAGE 28 2023-3779 ORD2023-16 7. Residential developments with no historic flooding where all the following conditions exist.This exception shall be supported by calculations provided by the Applicant. Additional information may be requested and will be signed and stamped by a Colorado Licensed Professional Engineer: a. Nine(9)lots or fewer. b. The minimum lot size is equal to,or greater than,three(3)acres per lot. Delete c.Downstream roadway criteria are not exceeded. c. The total post-development imperviousness for the rural residential development does not exceed ten percent(10%),assuming that all internal roads and driveways are paved. 8. Development of sites where the change of use does not increase the imperviousness of the site.Note:This exception cannot be applied to sites where impervious surfaces were added for,or in conjunction with,a business that is/was operating in violation and/or without the required Weld County land use permit. 9. A parcel of land or project site where the"total developed stormwater runoff'from the 100-year, 1-hour storm is less than, or equal to,five(5)cfs. The"total developed stormwater runoff'includes cumulative runoff from the proposed project site plus runoff from any previously developed project site on the subject parcel. A project site is the area of land that lies within the project's limits of disturbance during construction. This exception shall be supported by calculations signed and stamped by a Colorado Licensed Professional Engineer. 10. In-fill development parcels with total area less than,or equal to,one(1.0)gross acre. 11. An individual parcel with an unobstructed flow path and no other parcel(s)between the channel within a Federal Emergency Management Administration(FEMA) regulatory floodplain and the project. 12. A parcel greater than one(1)gross acre and less than,or equal to,five(5)gross acres in size is allowed a onetime exception for a new four thousand(4,000)sq. ft.of 100%impervious area or equivalent imperviousness.(See Appendix 8-Q in the Weld County Engineering and Construction Criteria Manual for impervious value percentages). 13. A parcel greater than five(5)gross acres in size is allowed a onetime exception for a new nine thousand(9,000)sq.ft.of 100%impervious area or equivalent imperviousness. (See Appendix 8-Q in the Weld County Engineering and Construction Criteria Manual for impervious value percentages). 14.No change. PAGE 29 2023-3779 ORD2023-16 Amend Sec.8-11-50.Rainfall. The designer shall use the most appropriate and best available data for the project area in determining the rainfall quantities.The applicant shall utilize local rainfall data from the National Oceanic and Atmospheric Administration(NOAA)unless otherwise approved by Weld County. The use of synthetic rainfall distribution data is not permitted. Amend Sec.8-11-60.Runoff. A. The Rational Method should not be used to determine runoff for basins larger than one hundred sixty(160)acres.In areas located in the southwest portion of Weld County, where areas are larger than one hundred sixty(160)acres SWMM is required. Delete B.Amend Sec.8-11-70.Street drainage for use by special review,commercial, industrial,planned unit development and residential subdivisions. A.—No change. B. Inlets. 1. The design guidelines provided in the streets/inlets/storm sewers chapter of the MHFD Manual(Volume 1)should be used when designing stormwater inlets.The standard inlets permitted for use in Weld County streets/roads are shown in the following table: Remainder of 1.and 2.(including both tables)—No change. C. Pipes. 1. The design guidelines provided in the streets/inlets/storm sewers chapter of the MHFD Manual(Volume 1)should be used when designing stormwater pipes. Remainder of section—No change. Amend Sec.8-11-80.Major drainage. A.—No change. B. Open Channel Design Principles. 1. Grass-lined open channels conveying less than fifty(50)cfs may reduce the minimum 1.0-foot freeboard requirement to the freeboard required to convey 1.33 times the 100-year design flow.The reduced freeboard may only occur if a 1.0- foot minimum freeboard is not physically possible,and calculations are submitted and accepted by Weld County. PAGE 30 2023-3779 ORD2023-16 2. Generally,channels and swales should be no steeper than 4:1.If steeper slopes are required due to site constraints,the design engineer shall address how the channel will be maintained. Amend Sec.8-11-90.Culverts in County road right-of-way. A. Sizing. 1. The applicant shall contact Weld County to determine which types of storm sewer pipes are permissible for use in County road rights-of-way or public drainage easements. 2.—No change. B. Materials.Culverts that are to be installed in a County road right-of-way that is routinely burned must be made of either concrete or metal.Pipes made of flammable materials (such as PVC or HDPE)will not be allowed in County road rights-of-way that are subject to weed burning. Amend Sec.8-11-100.Storage. A. Detention Criteria. 1.and 2.—No change. 3. Off-site flows can be routed over the spillway or routed around the site. Delete a. Delete b. 4. The elevation of the top of the detention pond embankment,except at the spillway, must be a minimum of 1-foot of freeboard above the 100-year water surface elevation in the detention pond. 5. Outlet structures should be sized and structurally designed to release at no more than the 1-hour,5-year historic release rate in urbanizing drainage areas and 1- hour, 10-year historic release rate in non-urbanizing drainage areas without structural or hydraulic failure.Historic is defined as an undeveloped site with a 2.0%imperviousness.The outlet pipe must contain a minimum of two concrete cutoff walls embedded a minimum of eighteen(18)inches into undisturbed earthen soil.The cutoff walls must be a minimum of eight(8)inches thick.The outlet pipe bedding material must consist of native earthen soil,not granular bedding material, to at least the first downstream manhole or daylight point. 6.—No change. 7. A concrete cutoff wall eight(8)inches thick,three(3)feet deep,and extending a minimum of five(5)feet into the embankment on each side of the emergency PAGE 31 2023-3779 ORD2023-16 spillway opening, is required on all privately-maintained detention ponds and regional detention ponds. The concrete cutoff wall permanently defines the emergency spillway opening.The emergency spillway elevation must be tied back into the top of the embankment using a maximum slope of 4:1. 8.and 9.—No change. B. Retention Criteria. 1.thru 3.—No change. 4. The design of the retention facility must provide evidence that the pond will drain in accordance with C.R.S.37-92-602(8),as amended,when only draining through the bottom of the pond(side slopes cannot be used in the calculation).A retention pond that can cause injury to water rights or is in violation of state or federal law will not be accepted. C. Erosion Protection Design Criteria. Erosion protection for storage facilities must be designed to prevent erosion and ensure that the sediment does not leave the site or impact downstream properties.It will be necessary to leave erosion control measures in place until one season of growth and the site reaches final stabilization(70%vegetative cover). The Control Measures/BMPs outlined in the MHFD Manual(Volume 3)should be used. Amend Sec.8-11-110.Revegetation. A. Weld County utilizes the information provided in the Revegetation Chapter of the MHFD Manual(Volume 2),and the Best Management Practices Chapter of the MHFD Manual (Volume 3).Weld County has highly recommended seed mixes that are applicable to specific areas of the County.These seed mixes can be found in the Weed Management Section of the Weld County Public Works Website.Noxious weeds shall be controlled on site,pursuant to Chapter 15,Articles I and II,of the Weld County Code. B. Seeding and Planting. In addition to the site preparation guidelines outlined in the revegetation chapter of the MHFD Manual(Volume 2),if mulching with straw,the straw must be free of seeds and weeds. Amend Sec.8-11-120.Stormwater quality. A. A water quality feature improves the quality of stormwater runoff resulting from the impacts of site development.A water quality feature can be an existing low spot on a property that naturally collects water,or it can be an area on a property that has been excavated to capture stormwater runoff.The required water quality capture volume of a feature is based on the site's size and imperviousness.A properly sized feature will capture and hold stormwater runoff for the period of time necessary for contaminants to settle out before stormwater runoff is allowed to exit the site. B. An accepted methodology for a water quality feature design can be found in the MHFD Manual,Volume 3,Best Management Practices. PAGE 32 2023-3779 ORD2023-16 Remainder of section—No change. Amend Sec.8-11-130.Control measures. Weld County uses the Control Measures/BMPs that are outlined in the MHFD Manual (Volume 3)Best Management Practices. Amend Sec.8-11-140.Maintenance. A. Culverts located outside of County-maintained road rights-of-way are not maintained by Weld County.The owners of those culverts are responsible for their maintenance.Culverts that are part of a subdivision drainage plan are maintained by the respective homeowner's association.Those culverts should be maintained and cleaned out annually, per the drainage report maintenance plan,or on an as-needed basis to ensure proper drainage of the subdivision. B.thru D.—No change. E. Areas designated for stormwater storage,retention,or detention are not to be used for storage of materials,building,or parking,or modified without approval from Weld County. Amend Sec.8-11-160.Stormwater drainage criteria variances. The variance procedure is intended to address cases of hardship. Relief from the provisions of this article may not be granted when the hardship is brought about solely through the actions of the appellant.No relief may be granted when the result of granting the requested relief is detrimental to the public health,safety,and general welfare or when the relief is contrary to the purpose and intent of this article.In granting any variance,Weld County may prescribe appropriate conditions and safeguards in conformity with this article.Violation of such conditions and safeguards,when made a part of the terms under which the variance is granted,shall be deemed a violation of this article. The variance request shall be stamped and signed by a professional civil engineer licensed to practice in the State of Colorado.Requests will be reviewed by the proper Weld County designee.In order to be granted,the variance request must meet the criteria as specified in Chapter 12 of the Weld County Engineering and Construction Criteria(Appendix 8-Q of the Weld County Code). Delete A.thru E. Remainder of section—No change. ARTICLE XII-Grading Permit Policy Amend Sec.8-12-10.General. The Grading Permit is a tool to ensure that the County has reviewed proposed grading plans and erosion and sediment control practices for planned construction activities with the goal PAGE 33 2023-3779 ORD2023-16 of avoiding potential damages and risks to the public.A Grading Permit grants the Permit Holder permission to conduct construction activities within the requirements of applicable state regulations and provides the County with sufficient oversight to minimize the potential for offsite damages.In addition,construction activities in the County must be compliant with applicable state regulations regarding releases of sediment and water from construction sites.This policy shall apply within all unincorporated areas of the County as of the effective date of this Article. Amend Sec.8-12-20.Purpose. This Article recognizes the importance of protecting the health,safety and welfare of the public,safeguarding County infrastructure,and the protection of water quality and private property rights.This Article describes the minimum requirements for prevention of detrimental or negative impacts to County water quality and damages to private property and County infrastructure by construction activities within the County.The goals are: A.thru C.—No change. Add D.To identify and eliminate any preventable damages to County infrastructure caused by construction activities. Add E.To ensure compliance with all Federal,State,and County laws and regulations pertaining to grading and water quality. Amend Sec.8-12-30.Grading Permit. A. Issuance of Grading Permit.A Grading Permit shall be issued only in compliance with the rules and regulations set forth in this Article.In no event shall construction be allowed or permitted if it is detrimental to the public health,welfare and safety or the grading and/or sediment and erosion control plans indicate that the construction activities will be out of compliance with Federal or State laws and regulations. B.-No change. C. No Work Without Permit.No person or entity may surface disturb,grade,construct or excavate over one(1)acre of nonexempted ground without first having obtained a Grading Permit from Weld County.In addition,no person or entity may grade,excavate,construct or leave disturbed and unstabilized over one(1)acre of nonexempted ground beyond the date or dates specified in the Permit unless:(1)the person or entity requests a written extension before the expiration of the initial Permit;and(2)a new Permit or extension is granted.It is a violation of this article to perform this work without a permit. D. Exemptions.The following land disturbance activities are permissible without obtaining a Grading Permit,unless otherwise located within a designated Municipal Separate Storm Sewer Systems(MS4)area. The Department shall determine if the exemption is in accordance with the County's MS4 permit.Other permits,such as right-of-way,flood hazard or OWTS,may still be required. 1.thru 4.—No change. PAGE 34 2023-3779 ORD2023-16 5. County capital improvement or County maintenance projects within a road right- of-way and temporary construction easements(TCE). 6.—No change. 7. Maintenance and resurfacing of existing streets/roads,parking/outdoor storage areas,runways,and sidewalks/trail systems. 8. Performance of emergency work necessary to prevent or mitigate an immediate threat to life or property when an urgent necessity arises.The person performing such emergency work shall promptly notify Weld County of the problem and work required.Any person performing such emergency work shall immediately notify Weld County of the situation and the actions taken.The Weld County Public Works and/or Planning Services Director may,however,require such person to obtain a Grading Permit to implement remedial measures to minimize erosion resulting from the emergency. 9.and 10.—No change. 11. Land disturbance associated with the construction of natural surface trails may be exempted by Weld County except within designated MS4 areas,provided that the procedure outlined in this Article is completed prior to commencement of any trail construction.If exempted,the land disturbance associated with the construction of natural surface trails shall generally conform with the performance standards of this Article. Amend Sec.8-12-40.Definitions. For the purpose of this Article,the following terms,phrases,words and their derivations shall have the meanings given herein: Add Construction dewatering permit:means the Colorado Discharge Permitting System (CDPS)General Permit COG080000,Construction Dewatering Discharges,which is regulated by the Colorado Department of Public Health and Environment,Water Quality Control Division. Add Construction stormwater permit:means the Colorado Discharge Permitting System (CDPS) General Permit COR400000, Stormwater Discharges Associated with Construction Activity,which is regulated by the Colorado Department of Public Health and Environment,Water Quality Control Division. Right-of-way(ROM):means a strip of land that is dedicated or granted to and accepted by Weld Couonty for transportation purposes,such as a roadway or highway,whether maintained or non-maintained by Weld County.The term is used as both singular and plural. Add Stormwater construction permit:is the state-issued permit for construction activity disturbing one(1)acre or more,including disturbance less than one(1)acre but is part of a larger common plan of development or sale. PAGE 35 2023-3779 ORD2023-16 Amend Sec.8-12-50.Grading Permit application. A. Complete Application Required.Applicants shall file a complete application for a Grading Permit.Based upon the information provided in the application,additional submittals may be required by Weld County if sufficient information was not provided for review of the application.An application shall be considered complete if it is submitted in the required form,includes all mandatory information,including all supporting materials specified by application,and is accompanied by the applicable fee.If an application is determined to be incomplete, Weld County shall provide notice to the applicant, along with an explanation of the application's deficiencies.No further processing of the application shall occur until the deficiencies are corrected in a future resubmittal.An application which is determined to be incomplete may,or may not,retain its same processing cycle. B. A complete application will typically include civil engineering drawings signed and sealed by a registered Civil Engineer in the State.The drawings shall include a grading plan(with existing and proposed contours,spot elevations,and earth balance when requested),and a drainage plan.In addition,a Sediment and Erosion Control Plan that shows the location and types of control measures to be utilized at the site shall be provided.Typical control measure installation details and maintenance notes should also be on the drawings. C.—No change. Amend Sec.8-12-60.Application review,Grading Permit issuance,permit expiration and permit extension. A. Review Process.The application and other data filed by an applicant for a Grading Permit shall be reviewed by Weld County.The application may also be reviewed by other departments or agencies to verify compliance with any applicable laws.If Weld County finds that the work described in an application for a Grading Permit conforms to the requirements and regulations set forth in this Article and meets the requirements defined in the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q)or other pertinent laws regulations or ordinances,and that all required fees have been paid,a Grading Permit shall be issued to the applicant.Criteria upon which the Grading Permit shall be considered include,but are not limited to,the following: 1.thru 3.—No change. B. Changes in a Weld County Grading Permit.AWeld County Grading Permit shall not be changed,modified or altered without written authorization from the County.All work shall be done in conformance with the Permit issued. C. Permit Limitations.An Weld County Grading Permit requires the Permit Holder to meet certain permit specifications and general engineering standards.Weld County shall be responsible for ensuring compliance with such specifications and standards.The issuing and granting of the Grading Permit shall not be construed to be a permit for,or an approval of,any violation of any of the provisions of this Article or of any Federal,State or County regulations.Additionally,the issuance of the Grading Permit shall not be construed as the approval or issuance of any necessary permits referred to in this Code. PAGE 36 2023-3779 ORD2023-16 D. Indemnification.Every Weld County Grading Permit issued shall include the following language:"Permit Holder,its agents,employees,subcontractors,contractors and assigns hereby agree to hold Weld County,Colorado,the agencies thereof and their officers and employees harmless from any and all loss and damage or any claims which may arise out of,or be connected with,the construction within the area covered by this permit;excluding any such loss and damage or any claims(including consequential damages)which may be caused solely by the negligence of Weld County,the agencies thereof or its officers and employees." E.—No change. F. Permit Expiration.Every Weld County Grading Permit shall expire one(1)year from the issuance of the permit.If the permit has expired,the Grading Permit must be reissued by the County before work can begin or be resumed.Prior to the expiration or closure of the Grading Permit,the disturbance shall be stabilized,and non-permanent control measures shall be removed. G. Permit Extension.Any Permit Holder with an unexpired Grading Permit may apply,in writing,for an extension of the time within which work may begin under that Grading Permit if the Permit Holder is unable to begin or complete work within the time required for good cause,and that the cause is acceptable to Weld County.There may be an extension fee assessed to cover administrative costs. Amend Sec.8-12-80.Permit Holder's general responsibilities. A Permit Holder is responsible for the following items.Additional requirements and more detailed information are shown in the Special Provisions of the Grading Permit. A. Control Measures.The Permit Holder shall ensure that all erosion and sediment control measures shown on the accepted plans are correctly installed and maintained. B. Other Permits.The Permit Holder shall secure all permits required by federal,state and local agencies.Written documentation from an outside agency stating that the grading activities do not require an agency permit shall be provided to the County when requested. C.—No change. D. Surety.If deemed necessary by Weld County,the Permit Holder shall provide a surety bond and/or other security for the total amount required to stabilize,restore or reclaim the disturbed ground to prevent erosion and/or release of sediment,excessive storm water and/or pumped water discharges to surface waters from the construction area. Said security shall remain in effect for a period of twenty-four(24)months after all completion of construction and establishment of erosional stability.The amount of the security shall be sufficient to stabilize a disturbed site to prevent releases of sediment and water from construction sites and protect the health,safety and welfare of the public.The amount shall be based on cost estimates of site restoration provided by the applicant and accepted by the County.Whether or not covered by surety,the Permit Holder shall reimburse the County for any and all expenses incurred by the County within twenty-four(24)months PAGE 37 2023-3779 ORD2023-16 after completion of any work as a result of,or related to,failure by the Permit Holder to perform all installation,construction,maintenance or other work pursuant to the Grading Permit,in a workmanlike manner. E.—No change. F. Traffic Control. Construction activities impacting the County rights-of-way shall not interfere with movement of traffic or compromise public safety.A County Right-of-Way Use Permit may be required in addition to a Grading Permit. G. Emergency Conditions. When a condition arises where emergency work must be performed,the applicant shall immediately notify the County of the emergency event,type and extent of work.Within two(2)business days after the occurrence of the emergency, the applicant shall apply for the necessary permits,pay the associated fees and fulfill the rest of the requirements necessary to comply with the Grading Permit for the actions the applicant took in response to the emergency. H.—No change. I. Site Stabilization, Restoration and Cleanup. The Permit Holder shall assume all responsibility for stabilizing the permitted site to prevent erosion and discharges of sediment.The Permit Holder shall also assume all responsibility for removing all debris associated with the construction activities in the County rights-of-way and all non- permanent control measures.If,upon inspection,the County determines that there is risk of erosional damage,or sediment discharges or debris has not been removed from the County rights-of-way,the County shall notify the Permit Holder of the violation of the Grading Permit conditions.The Permit Holder,upon notification from the County,shall correct all work to the extent necessary.The work shall be completed within the time period specified in the notice from the County.If the Permit Holder fails to establish site stability or restore the rights-of-way in the manner and to the condition required,the County may perform the restorations.In that event,the Permit Holder shall pay to the County,within thirty(30)days of billing,the cost of restoring the County rights-of-way. Remainder of section—No change. Amend Sec.8-12-90.Inspections. A. Inspections during the construction period may be made by the County to ensure that work is progressing in compliance with the Grading Permit.It shall be the responsibility of the Permit Holder to provide safe access to the work site for the County and to all others,as authorized by law,for inspection at all reasonable times during the execution and upon completion of the work.At the time of inspection,the County may order the immediate termination of any work which involves the unauthorized exportation of material,or which poses,or is causing,a serious threat to the life,health,safety or well-being of the public. B. It shall be the responsibility of the Permit Holder to notify the County when work is ready for inspection.Weld County requires that every request for inspection be received at least forty-eight(48)hours before such inspection.Such requests may be made by telephoning, PAGE 38 2023-3779 ORD2023-16 or emailing the Department of Planning Services.The presence of County employees on-site shall not guarantee or qualify the Permit Holder's performance.The Weld County Grading Permit must be available on-site for review by County staff.Failure to comply may result in suspension of the Grading Permit. C. To ensure compliance with this Article,the County may make,or require,inspections and/or testing of any work as deemed necessary.Work performed without the required inspections shall be subject to removal and replacement at the Permit Holder's expense, regardless of the quality of the work.Any inspection hours required outside of the normal working hours will be paid for by the Permit Holder.Certain types of work may require continuous inspection.When such projects exceed the County's ability to provide ample inspection,the Permit Holder will incur the cost for providing a private inspection firm to conduct inspectons as needed.This third-party inspector will be appointed by the County prior to issuance of the Grading Permit. Amend Sec.8-12-110.Appeal of denial of Grading Permit. If an application for a Grading Permit is denied by the County,or if the applicant objects to any of the terms or conditions of a permit thereby placed by the County,the applicant has the right to appeal the decision to the Board of County Commissioners,in writing,utilizing the appeal procedures set forth in Section 2-4-10 of this Code. Amend Sec.8-12-120.Failure to comply with terms of grading permit. A. The issuance of the Grading Permit based on plans,specifications or other data shall not prevent the County from requiring the correction of errors in the plans,specifications and other data,or from stopping excavation or construction operations being conducted in violation of this Article or any other state or County regulations.Failure of the applicant to comply with any of the terms and conditions of the Grading Permit shall be sufficient cause for cancellation of the Grading Permit. B. The Permit Holder shall prevent releases of sediment and water from construction sites that have the potential to cause damage to private property or County-maintained infrastructure.In the event that construction activities result in erosion or sediment and water discharges causing damage,the Permit Holder shall immediately attempt to prevent further harm, by installing or replacing appropriate control measures and correct any unsatisfactory work. C. Right-of-Way Damage.The Permit Holder shall correct any unsatisfactory work.Actions to remedy unsatisfactory work may include the patching and/or the removal and replacement of defective pavement.Other actions may be required.If the Permit Holder fails to restore the County rights-of-way in the manner and to the condition required by the Department of Public Works,or fails to satisfactorily and timely complete all restorations required by the Department of Public Works to a same or better condition,or in a timely manner,the County shall have the right to perform the restorations at the expense of the Permit Holder. PAGE 39 2023-3779 ORD2023-16 Amend Sec.8-12-130.Permit suspension or revocation. A. The County may deny,revoke or suspend any Grading Permit in order to protect the public health,safety and welfare.Permit Holders hold Grading Permits as a privilege.The County reserves the right to revoke any Grading Permit without a fee refund when the Permit is issued in error,based on incorrect information provided by the applicant,or when the Permit is issued in violation of any provisions of this Article. B. The grading permit will be suspended should the County determines that the Permit Holder has committed a substantial breach of the terms or conditions of any statute, ordinance,rule,or regulation,or any condition of the Grading Permit itself.Weld County will notify the Permit Holder of the Grading Permit suspension by either phone,or in writing,and mandate that the Permit Holder remedy the violation.The demand shall state that continued violations may be cause for revocation of the Grading Permit.Further,a substantial breach shall allow the County to place additional or revised conditions on the Grading Permit. C. Within twenty-four(24)hours of receiving notification of the suspension,the Permit Holder shall contact the County with a plan of correction which must be accepted.The Permit Holder's failure to contact the County,to submit an acceptable plan,or to reasonably implement the accepted plan shall be cause for immediate revocation of the Grading Permit and termination of work.Upon revocation of the Grading Permit,the Permit Holder will be required to re-apply for a new permit and will be charged for any additional fees that may be applicable. Amend Sec.8-12-140.Penalties. A. Violations and Penalties.The County,through the Departments of Planning Services and Public Works or other County departments so authorized,may enforce this Article through methods included in this Article or through other methods adopted by the Board of County Commissioners. Remainder of section—No change. ARTICLE XIII-Right-of-Way Use Permit Policy Amend Sec.8-13-10.General. The County strives to keep its road right-of-way in a state of good repair and free from unnecessary encumbrances.The Right-of-Way Use Permit is a tool to regulate and permit the use of Weld County's public road right-of-way by private companies,municipalities and/or special district constructing and burying lines either crossing or running parallel within Weld County road right-of-way.Crossings are allowed for all lines.Parallel installations are allowed for lines of "public utilities"that are defined in C.R.S.§40-1-103 and are"domestic or foreign electric light power, gas, or pipeline companies"holding current Certificates of Public Convenience and Necessity issued by the Colorado Public Utilities Commission;for water lines of municipalities, water districts,and water and sewer districts;for transmission lines or pipelines used solely for agricultural purposes;for fresh water above-ground transfer pipelines; and for lines in non- PAGE 40 2023-3779 ORD2023-16 maintained road right-of-way if approved by Weld County based upon locational factors,such as, surrounding population density,topography,or if the road right-of-way provides access to a recorded exemption lot,and with Permittee's agreement to move the line at its sole expense if Weld County or an annexing municipality intends to improve the road right-of-way;or if authorized by the Board of County Commissioners in an appeal of the denial of a Right-of-Way Use Permit application,pursuant to Section 8-13-110,below.Public road right-of-way subject to regulation by the Right-of-Way Use Permit includes Weld County's maintained and non-maintained road right-of-way,and all public drainage easements.A Right-of-Way Use Permit grants the Permittee and its Contractors permission to occupy designated County road right-of-way. The Permit authorizes excavation,surveying,and/or construction of facilities within the County road right-of- way and provides for their subsequent restoration upon completion of the Project.This Policy shall apply within all unincorporated areas of the County. Amend Sec.8-13-20.Purpose. This Article recognizes the importance of protecting the health,safety and welfare of the traveling public,maintaining efficient traffic flow and preserving the integrity of Weld County's road right-of-way. Amend Sec.8-13-30.Regulation of work in county road right-of-way. A. Issuance of Right-of-Way Use Permit.A Right-of-Way Use Permit shall be issued only in compliance with the rules and regulations set forth in this Article. In no event shall construction within the County road right-of-way be allowed or permitted if it is detrimental to the public health,welfare and safety. B. Right-of-Way Use Permit Necessary. A Right-of-Way Use Permit is required for occupying,constructing,maintaining or excavating facilities within,and for encroaching upon,any County road right-of-way. C. No Work Without Right-of-Way Use Permit.No person or entity may occupy,construct, perform maintenance or excavate within any County road right-of-way or easement,or encroach upon any County rights-of-way or easement,without first having obtained a Right-of-Way Use Permit from the Department of Public Works.In addition,no person or entity may excavate, construct, perform maintenance or occupy the County road right-of-way beyond the date or dates specified in the permit unless:(1)the person or entity requests a written extension before the expiration of the initial permit,and(2)a new permit or extension is granted. Amend Sec.8-13-40.Definitions. For the purpose of this Article,the following terms,phrases,words and their derivations shall have the meanings given herein: Permittee means the owner,operator,person and/or entity constructing,excavating or occupying the County road right-of-way who has obtained a permit pursuant to this Article. PAGE 41 2023-3779 ORD2023-16 Right-of-Way(ROM)means a portion of land that is dedicated or granted to and accepted by Weld County for transportation purposes,such as a roadway or highway whether maintained or non-maintained by Weld County.The term is used as both singular and plural. Remainder of definitions—No change. Amend Sec.8-13-50.Right-of-Way Use Permit application. Complete Application Required. Applicants shall file a complete application for a Right-of-Way Use Permit. Based upon the information provided in the application,additional submittals may be required by the Department of Public Works if sufficient information was not provided for review of the application.An application shall be considered complete if it is submitted in the accepted form, includes all mandatory information, including all supporting materials specified by application.If an application is determined to be incomplete,the Department of Public Works shall provide notice to the applicant, along with an explanation of the application's deficiencies. No further processing of the application shall occur until the deficiencies are corrected in a future resubmittal.An application which is determined to be incomplete may or may not retain its same processing cycle.The Right-of-Way Use Permit is found in Appendix 8-P,the terms and conditions of which are incorporated into this Article. Amend Sec. 8-13-60. Application review, Right-of-Way Use Permit issuance, permit expiration and permit extension. A. Review Process.The application and other data filed by an applicant for a Right-of-Way Use Permit shall be reviewed by the Department of Public Works.The application may also be reviewed by other departments or agencies to verify compliance with any applicable laws.If the Department of Public Works finds that the work described in an application for a Right-of-Way Use Permit conforms to the requirements and regulations set forth in this Article,meets the requirements defined in the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q)or other pertinent laws regulations or ordinances,and that all required fees have been paid,a Right-of-Way Use Permit shall be issued to the applicant. Criteria upon which the Right-of-Way Use Permit shall be considered include,but are not limited to,the following: 1. Safety:Occupation,construction,maintenance or excavating within the County road right-of-way must not create a safety hazard to the travelling public. 2. Constructability:All construction or excavation within the County right-of-way must be able to be performed according to general construction practices. B.—No change. C. Permit Limitations.An approved Right-of-Way Use Permit requires the Permittee to meet certain permit specifications and general engineering standards when working within the Weld County road right-of-way.The Department of Public Works shall be responsible for ensuring compliance with such specifications and standards.Reasonable care should be used to avoid damaging the existing roadway and/or County road right-of-way.The issuing and granting of the Right-of-Way Use Permit shall not be construed to be a permit for,or PAGE 42 2023-3779 ORD2023-16 an approval of,any violation of any of the provisions of this Article or of any regulations of the County. D. Indemnification.The Permittee,its agents,employees,subcontractors,Contractors and assigns,hereby agrees to hold Weld County,Colorado,the agencies thereof and their officers and employees harmless from any and all loss and damage or any claims which may arise out of, or be connected with,the construction, installation, maintenance, alteration,removal or presence of the lines installed and/or constructed herein referred to or any work or facility connected therewith,within the area covered by this permit; excluding any such loss and damage or any claims(including consequential damages) which may be caused solely by the negligence of the County,the agencies thereof or its officers and employees. The Permittee fully understands that all line installation, construction,maintenance and relocation will be performed at no expense whatsoever to the County. E. Permit Expiration. Every issued Right-of-Way Use Permit shall expire if the work authorized by the permit has not substantially begun within three(3)months from the date of the permit issuance or if the construction of work authorized by the permit is suspended or abandoned for a period of one(1)year at any time after the work has begun.Before work can begin or be resumed,a new permit must be applied for and reissued by the Weld County Department of Public Works. F. Permit Extension.Any Permittee with an unexpired Right-of-Way Use Permit may apply, in writing,for an extension of the time within which work may begin or be completed under that permit if the Permittee is unable to begin and complete work within the time required for good cause,and that the cause is acceptable to the Weld County Department of Public Works.If Permittee does not apply prior to the Permit expiring,the Permittee shall reapply for a new Permit. Projects in progress under and expired Permit shall suspend work until a new permit is issued.There shall be an extension fee assessed to cover administrative costs. Amend Sec.8-13-70.County authority. A Right-of-Way Use Permit is considered to be a license for use of the County road right- of-way.The Department of Public Works shall have the authority to suspend work,wholly or in part,because of the failure of the Permittee to properly execute the work in accordance with this Article.Weld County,notwithstanding the issuance of any permit or construction in Weld County road right-of-way, reserves the right to make any changes, additions, repairs or required relocation of any facilities within the dedicated road right-of-way at any time including,but not limited to,in connection with the relocation,reconstruction,widening and maintaining roads or road right-of-way,without compensating the owner. Amend Sec.8-13-80.Permittee's general responsibilities. The Permittee is responsible to comply with all of the terms and conditions set forth in this Article and the Right-of-Way Use Permit found in Appendix 8-P. PAGE 43 2023-3779 ORD2023-16 Amend Sec.8-13-90.Inspections. A. Inspection of work performed within Weld County road right-of-way, pursuant to an approved Right-of-Way Use Permit,is required.Inspections during the construction period will be made by the Weld County Department of Public Works to ensure that work is progressing in compliance with the Permit. If at any time during an inspection it is determined work is out of compliance with the Permit or there is a safety concern,a stop work order shall be enforced until compliance has been returned. It shall be the responsibility of the Permittee to provide safe access to the work site for the Department and to all others,as authorized by law,for inspection at all reasonable times during the execution and upon completion of the work.At the time of inspection,the Department may order the immediate termination of any work which poses a serious threat to the life, health,safety or well-being of the public. B. It shall be the responsibility of the Permittee to notify the Department of Public Works when work is ready for inspection.The Department requires that every request for inspection be received at least forty-eight(48)hours before such inspection.Such requests may be made by telephoning, or emailing the Department. The presence of Department employees on-site shall not guarantee or qualify the Permittee's performance. The approved permit must be available on-site for review by Department staff. Failure to comply will result in suspension of the Permit. C.—No change. Amend Sec.8-13-100.Administrative fee. All required fees shall be paid in full prior to Permit issuance.The fee schedule for Right- of-Way Use Permits shall be as determined by resolution of the Board of County Commissioners and shall be shown on the permit.If the applicant objects to the denial of a permit application by the Weld County Department of Public Works,or objects to any of the terms or conditions of a permit thereby placed by the Department,the applicant has the right to appeal the decision to the Board of County Commissioners,in accordance with the procedures detailed in Section 12-4-110, below. Amend Sec.8-13-110.Appeal of denial of Right-of-Way Use Permit. Remainder of section—No change. Amend Sec.8-13-120.Failure to comply. A.—No change. B. The Permittee shall correct any unsatisfactory work including,but not limited to,defects in removal,replacement or patching.If the Permittee fails to restore the Weld County road right-of-way in the manner and to the condition required by the Weld County Department of Public Works or fails to satisfactorily and timely complete all restorations required by the Department,the County shall have the right to perform the restorations at the expense of the Permittee. PAGE 44 2023-3779 ORD2023-16 C. Weld County reserves the right to require relocation of any facilities within the dedicated road right-of-way at any time without compensating the owner. If the Contractor or Permittee does not perform the required relocation within four(4)months of notification from the Weld County Department of Public Works,no new permits will be issued from the Department of Public Works for the contractor until the relocation has been accomplished. Amend Sec.8-13-140.Enforcement. A.—No change. B. Criminal Penalties. 1. It is unlawful to occupy, construct or excavate within any Weld County road right-of-way or encroach upon any County right-of-way,unless a Right-of-Way Use Permit is first issued.Any person,firm or corporation violating any provision of this Article is guilty of a Class 2 petty offense,which,upon conviction thereof,shall be punishable by a fine of three hundred dollars($300.00)or by imprisonment in the County jail for not more than ten(10)days,or by both such fine and imprisonment, for each separate violation.Each day during which such violation continues shall be deemed a separate offense. Remainder of section—No change. ARTICLE XIV-Road Access Policy Amend Sec.8-14-10.Intent of road access policy. This Article XIV is established for the safe and efficient movement of traffic while allowing reasonable and safe access to properties.It is necessary to protect the public health,safety and welfare to maintain conventional traffic flow along with unobstructed roadside drainage and to protect the functional integrity(safety, mobility, and capacity) of County roadways.Access management is an important tool in transportation planning,which identifies the safety,spacing and location of driveways,median openings,and the interconnectivity of road classifications to maintain the access and mobility function of collector and arterial roads.This Article XIV shall apply to all accesses utilizing County rights-of-way within the unincorporated area of Weld County. Amend Sec.8-14-20.Purpose and intent. The purpose of access management is to manage the safety of existing and proposed accesses adjacent to land uses on County roads to ensure that safety,capacity,and function are preserved and a reduction in conflict points occurs.This Article XIV describes the minimum requirements for the design,construction and maintenance of accesses onto Weld County road rights-of-way and requires the issuance of an access permit prior to construction. Amend Sec.8-14-30.Regulation of access onto County roadways. A. Access to a Single Parcel.Each parcel shall be limited to one(1)safe access point for PAGE 45 2023-3779 ORD2023-16 safe ingress and egress,which may be an existing or new shared access,except if allowed pursuant to Subsection E.,below. B. Access Permit Required.An access permit shall be required for any of the following: 1. Constructing a new safe access onto a County road right-of-way, 2. Reconstructing, paving, altering, relocating, or enlarging an existing access location, 3. Changing the use or type of traffic of any existing access location,or 4. Increasing the amount of traffic using an existing access location. C. Issuance of Access Permit.Access Permits shall be issued only in compliance with the rules and regulations set forth in this Article XIV.In no event shall an access be allowed, or permitted,if it is detrimental to the public health,welfare,and safety.No such work shall commence prior to the issuance of an Access Permit. D. Emergency Access Allowed.Police,fire,ambulance and other emergency providers may have direct access to County roadways,on a case-by-case basis,if no other access is permitted.If allowed,the emergency access shall be gated and include a Knox box,or other types of safety improvements. E. Additional Access.Additional accesses to a parcel may be allowed if the applicant demonstrates a need for more than one access,the proposed accesses comply with the spacing criteria for that road,and no other safety concerns exist(e.g.sight distance concerns).If a new access is requested that does not meet the spacing criteria to a legal parcel where an existing access already exists, the additional access shall not be approved unless the denial of the new access would create undue hardship on the property owner,as determined by Weld County.Whenever multiple accesses to a single legal parcel exist, and additional accesses are requested, one(1)or more existing accesses must be removed,minimizing new accesses,and utilizing existing accesses. F. Access Permit a Condition of Building Permit. 1. When a new or upgraded access locationis to be constructed in conjunction with any construction authorized by a building permit,the issuance of an access permit shall be a condition for obtaining a building permit for such construction. 2. When the property owner intends to use a Historical Access Location in conjunction with any construction authorized by a building permit,the property owner shall apply for a new access permit for any existing access location never previously permitted.Unless otherwise required by this Article XIV,such access permit shall not require the closure,relocation,upgrade,or any other physical change to the Historical Access Location and shall be for the purpose of identifying the Historical Access Location. In that circumstance the property owner shall not be charged an access permit application fee. PAGE 46 2023-3779 ORD2023-16 G. Definitions. Access means the physical location where vehicles enter onto a maintained County road right-of-way. Change in Type of Traffic means a change to the type of vehicles that use the existing access location,including but not limited to,a change from passenger vehicles to semi- trucks,or a change from agricultural equipment to passenger vehicles. Change of Use means a change in how a parcel that accesses onto a County road right-of-way is used,regardless of whether the parcel is within the unincorporated part of the County. Change of Use includes the construction of additional principal structures (e.g.homes,offices,etc.),the increase of intensity of an existing use(e.g.expansion of an existing business,etc.),change in zoning,change in lot lines,creation of new parcels, and other land use changes. Change of Use does not include construction of accessory structures,remodeling of existing structures that does not increase traffic to the site,or similar changes. Historical Access Location means an unpermitted access that was constructed and in-use prior to the date that this Access Code was originally approved,July,1,2010. Unless there is a safety concern,Historical Access Locations may continue to be used in the manner they were historically used prior to that date. Any Change of Use,Change in Type of Traffic,increase in amount of traffic,or change to the physical location of the Historical Access Location(e.g.enlarging,reconstructing,paving,or otherwise altering) shall require a new access permit. Illegal Access means an unpermitted access that has been constructed or used when otherwise required to obtain an access permit. Illegal Accesses do not include Historical Access Locations that are used in the manner they were historically used prior to the original approval of this Access Code. H. Access Approval as a Condition of a Land Use Case.When an existing,or shared access is to be utilized in conjunction with a land use case,the plat map shall identify the preliminary approved access location prior to recording the plat.The property owner shall apply for an access permit when ready to construct the access and may be required to enter into an improvements and road maintenance agreement. I.—No change. Table 1—Minimum Access Spacing Criteria(Feet)—No change. Add J.Closure/Upgrade/Relocation of Accesses Presenting Safety Concerns. Weld County has the authority to order an existing access location(whether permitted,historical,or illegal) to be closed, upgraded,or relocated whenever it determines that a significant safety concern exists. Such action shall be made at the property owner's expense. PAGE 47 2023-3779 ORD2023-16 Amend Sec.8-14-40.Access permit application process. A. Submittal Requirements;Complete Application.An application for an access permit shall be considered complete if it is submitted on the required form,includes all mandatory information,including all supporting materials and is accompanied by the applicable fee. The application must be signed by the property owner or,if applicable,an authorized agent.Written authorization to act on the property owner's behalf may be accepted if the access application is not signed by the property owner.If an application is determined to be incomplete,the Department of Planning Services shall provide written notice to the applicant,along with an explanation of the application's deficiencies.No further processing of the application shall occur until the deficiencies are corrected in a future resubmitted application.An application which is determined to be incomplete may or may not retain its same processing cycle. B. Subdivision or Common Development Plan Access.Upon approval Weld County may require one(1)access permit at the location where the proposed common development plan or subdivision accesses to the County road to reduce the administrative burden on staff and applicants requesting permits concurrently for multiple lots.Such"development access"is subject to a development review application. C.—No change. D. Review Process.The application and information provided by an applicant for an access permit shall be reviewed by Weld County.The application may be reviewed by multiple departments or agencies to verify compliance with any applicable laws and codes.If Weld County finds the information and supporting documentation in the application for an access permit conforms to the policies and requirements set forth in this Article XIV,meets the requirements defined in the Weld County Engineering and Construction Criteria,as shown in Appendix 8-Q,or in other pertinent laws,regulations or ordinances,and that all required fees have been paid,an access permit shall be issued to the applicant. E. Changes in Approved Permit.An approved permit shall not be changed,modified or altered without written authorization from Weld County. All work shall be done in conformance with the approved permit. F. Permit Limitations.An approved access permit expires after one(1)year from its date of issuance and requires the permit holder to meet the specifications and general engineering standards of the Weld County Engineering and Construction Criteria, as shown in Appendix 8-Q.The proper Weld County staff shall be responsible for ensuring compliance with such specifications and standards. Remainder of section—No change. Amend Sec.8-14-50.Permit holder's general responsibilities. A permit holder is responsible to comply with the general provisions of this Code,including temporary accesses permits issued for the following items:Additional requirements and more detailed information are shown in the special provisions of the access permit. PAGE 48 2023-3779 ORD2023-16 A.—No change. B. Traffic Control.Access construction activities should not interfere with traffic on County roadways.If interference with traffic is necessary,a traffic control plan shall be submitted to,and approved by,the Department of Public Works as part of a Right-of-Way Permit application.All traffic control shall conform to the most current version of the Manual on Uniform Traffic Control Devices standards,which is available for review on the Federal Highway Administration website.All regulatory signs require approval of the Board of County Commissioners.If applicable,the permit holder shall be required to install all necessary signage and shall bear all expenses for the fabrication and installation of road name signs,permanent barricades,and signs required as part of a development project (e.g.,one way,no parking,no outlet,stop sign,speed limit,etc.). C.—No change. D. Tracking control.Permanent vehicle tracking controls provide stabilized site access where vehicles exit a location onto a paved road.Vehicles are required to perform a complete revolution of all tires prior to entering a County-maintained roadway.Effective vehicle tracking control helps remove sediment(mud or dirt)from vehicles.Commercial,industrial, or high traffic volume accesses shall provide permanent tracking control devices,which include,but are not limited to,double cattle guards or a paved(asphalt/concrete)tracking pad extending three hundred(300)feet into the site to mitigate impacts to the paved road, including damages and/or offsite tracking of mud or other materials. Requests for temporary tracking control techniques must be approved by Weld County prior to installation. Temporary tracking control shall be used during construction unless permanent tracking control is installed ahead of construction activities;such devices include,but are not limited to,crushed natural aggregate(recycled crushed concrete or asphalt shall not be used for any vehicle tracking pads)along with a geotextile fabric or pre-fabricated vehicle tracking pads with approved dimensions.Use-by-right permitted agricultural accesses are exempt from tracking control requirements.Tracking control is required for construction of accesses to prevent tracking from the site onto paved public roadways. The permit holder may be held financially responsible for damage to the roadway resulting from inadequate tracking control.All tracking control devices and designs must be in accordance with the Weld County Engineering and Construction Criteria,Appendix 8-Q. E. Access Construction, Restoration and Clean-up.The permit holder is responsible for installation of the correct culvert size(s),materials,and the cost of installation for new access culverts whenever the installation of a culvert is made necessary by the creation of a new access from private property to a county roadway. Accesses should be constructed in a manner that minimizes erosion and does not result in disposition of silt and debris upon the county roadway or roadside ditches.Accesses which slope down toward the County road will be constructed to assure that water does not run onto or across the traveled public way.This may include designing the crown,borrow ditches, pans,or other elements so that they direct water to the existing drainage facilities along the road. The permit holder shall assume all responsibility for removing all debris associated with the access construction activities and restoring the County roadway to pre-existing conditions.The access permit may allow construction of the access without PAGE 49 2023-3779 ORD2023-16 the need for obtaining a separate Right-of-Way Use Permit pursuant to this Chapter. Installation of commercial/industrial access(es)may require a traffic control plan to be approved with the access permit. the permit holder, upon notification from the Departments of Public Works and/or Planning Services, shall correct any items not consistent with the approved access permit within fourteen(14)days.If the permit holder fails to restore the road right-of-way in the manner and to the condition required by the Departments,the County may remove the access or perform the restorations and invoice the permit holder for the expense(s)incurred by the County. F. Access Sight Distance.Sight distance is essential to protect the traveling public at all access points along County roadways.Sight distance is the length of roadway that is clearly visible to the driver and is dependent upon the height of the driver's eye above the road surface,the specified object height above the road surface,and the height of sight obstructions within the line of sight.The minimum sight distance available on a roadway must be sufficient to enable a vehicle traveling at or near the design speed to stop before reaching a stationary object.In evaluating the overall performance of a roadway,both the horizontal and vertical sight distances must be considered.When items such as walls, buildings,bridge piers,cut slopes,or vegetation growth are near the roadway on the inside of a curve,they can block a driver's view of the road ahead.If they are too close,the driver will not have sufficient distance along the curved roadway to stop when a hazardous condition comes into view.The minimum requirements and technical criteria for sight distance are in the Weld County Engineering and Construction Criteria Manual,Appendix 8-Q. Amend Sec.8-14-60.Variance from specific access permit requirements. A property owner may request a variance from specific requirements set forth in this Article XIV.Weld County will consider requests for variances on a case-by-case basis.Requests for variances may be submitted in a written letter to Planning Services addressing the hardship or justification for the variance and supporting documentation to explain why they cannot comply with the requirements of this Article or as outlined in the Weld County Engineering and Construction Criteria,Appendix 8-Q.Requests will be reviewed and acted upon by the Planning Services Director or designee to ensure they will adequately protect the public health,safety,and welfare.Weld County staff will respond with an approval or denial in writing within thirty(30)days of receipt of the variance request. Amend Sec.8-14-70.Appeal of denial of access permit. If an access permit is denied by Weld County staff,or the applicant objects to any of the terms or conditions of a permit thereby placed by the County,the applicant has the right to appeal the decision to the Board of County Commissioners,in writing,utilizing the appeal procedures set forth in Section 2-4-10 of this Code. Amend Sec.8-14-80.Enforcement. A. Violations and Penalties.The County,through the Department of Planning Services or other departments so authorized,may enforce this Article XIV through methods included in this Section,or through other methods adopted by the Board of County Commissioners. PAGE 50 2023-3779 ORD2023-16 B. Criminal Penalties. 1.—No change. 2. Whenever the Department of Public Works and/or Planning Services,through one (1)of its employees,has personal knowledge of any violation of this Article XIV,it shall give written notice to the violator to correct such violation within sixty(60) days after the date of such notice.Should the violator fail to correct the violation within such sixty(60)day period,the Departments of Public Works and/or Planning Services may request that the Sheriffs Office issue a summons and complaint to the violator,stating the nature of the violation with sufficient particularity to give notice of said charge to the violator.The summons and complaint shall require that the violator appear in court at a definite time and place stated therein to answer and defend the charge.One(1)copy of said summons and complaint shall be served upon the violator by the Sheriff's Office in the manner provided by law for the service of a criminal summons.One(1)copy each shall be retained by the Sheriff's Office and Department of Planning Services and one(1)copy shall be transmitted to the Clerk of the Court.The County may install barriers across or remove any access not conforming to this Article XIV during the pendency of the enforcement action. 3.and 4.—No change. C.thru E.—No change. F. Inspections.The Departments of Public Works and/or Planning Services or other County departments may conduct an inspection of each access that is the subject of the access permit to ensure full compliance with all provisions of this Article XIV and the terms of the permit. G.—No change. H. Access Permit Issued Erroneously or Upon Incorrect Information.Any access permit which has been issued in error or on the basis of incorrect information supplied by the permit holder,shall be considered void.In the event an access permit is void,no refund of permit fees shall be made unless the access permit was issued in error by Weld County staff. I. Notice Regarding Illegal Access.For an illegal access,the property owner shall be sent written notice of any illegal access location or use.The owner shall be given sixty(60) days notification of pending actions,after which the County may install barriers across,or remove,any access not conforming to this Article XIV.Any access,driveway or curb-cut being constructed within County road right-of-way without an approved access permit shall be required to stop work immediately and apply for an access permit.If the permit is approved,work may continue subject to the conditions of the permit.If the permit is denied, any work that has been completed must be removed and the road and drainage facilities PAGE 51 2023-3779 ORD2023-16 returned to pre-existing conditions acceptable to the Department of Public Works and Planning Services,upon completion of any appeal or the time for appeal pursuant to the provisions of Section 8-14-70,above. Amend Sec.8-14-90.County authority. Notwithstanding the issuance of any access permit or the construction of any access, Weld County reserves the right to make any changes, additions, repairs, conditions, and relocation or closure of any part of an access within the County road right-of-way at any time, including, but not limited to, in connection with the relocation, reconstruction,widening and maintaining of the road or right-of-way,without compensating the owner of the access for the damages to or destruction of the access. Amend Sec. 8-14-100. Access Control Plans (ACP's), and additional techniques and requirements for access on County roads. A.and B.—No change. C. Access Control Techniques.A reduction in accesses onto a County road will improve traffic flow,operations,and safety of the traveling public.To reduce the number of existing access points,applicants may be required to implement the following access control techniques to reduce conflicts while maintaining adequate access to adjacent land uses. 1. Elimination.Applicants may be required to eliminate accesses identified as unsafe locations,where there are more than two(2)existing accesses for a parcel,or do not meet spacing requirements identified in the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q). C.2.thru D.—No change. E. Auxiliary Turn Lanes.Auxiliary lanes maintain the safety,traffic flow,and operation of a roadway or access.Auxiliary lanes are required when unique location factors exist such as roadway speed and traffic density,access volume,the volume of commercial trucks, the influence of nearby accesses,existing auxiliary lanes close to the proposed access, nearby traffic control devices,available stopping sight distance,and other topographic or roadway design factors.When applicable,the access permit holder is responsible for design, installation, any road right-of-way acquisition needed to accommodate the required lane width. Required auxiliary turn lanes must be installed according to the following traffic triggers: 1.thru 3.—No change. 4. A left turn acceleration lane with transition taper may be required if it would benefit the safety and operation of the roadway.A left turn acceleration lane is generally not required when the acceleration lane would interfere with the left turn ingress movements to any other access.Further auxiliary lane design criteria can be found in the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q). PAGE 52 2023-3779 ORD2023-16 F. Closure or Elimination of access.When an access is closed,abandoned or eliminated the permit holder shall assume all responsibility for any activities related to the closure/elimination and reclamation of access points stipulated to be removed.In the event the issuance of an access permit requires an existing access point to be"closed and reclaimed"it shall be completed by the stipulated date on the permit.If the county is closing an access,the property owner will be notified in writing,prior to the closure occurring of the date the County will close the access.Closure and reclamation activities may include,but are not limited to,reestablishing the profile of the burrow ditch,removing any culverts and gates in the fencing adjacent to the maintained road right-of-way,and attempting to reseed the affected area located in the road right-of-way with natural vegetation to the satisfaction of the Department of Public Works and Planning Services. G. Roadway Improvements.Projects with high traffic/trip generation or safety concerns may require public improvements; including but not limited to, auxiliary lanes, such as acceleration and deceleration lanes,exclusive left or right-hand turn lanes,or a traffic signal,in accordance with the Weld County Engineering and Construction Criteria Manual, as shown in Appendix 8-Q.If these types of roadway improvements are required,the permit holder will be responsible to enter into an improvements agreement with collateral. The agreement shall be approved by the Board of County Commissioners. Remainder of section—No change. ARTICLE XV-Transport Permits Amend Sec.8-15-40.General provisions. A.thru B.6.—No change. B.7. Travel routes may require build outs of turning radii or other road improvements necessary to accommodate movement of the Vehicle/Load.A Right-of-Way Use Permit may be applicable. Remainder of section—No change. Amend Sec.8-15-50.Transport permits types. The following Transport Permits are available as determined by the Department of Public Works for the movement of Extra-legal Vehicles and Loads on roadways under Weld County jurisdiction: A.thru E.—No change. Delete F. Amend Sec.8-15-60.Transport permits application information. A. The Maximum Limits authorized for Annual Extra-legal Vehicles or Loads are as follows: PAGE 53 2023-3779 ORD2023-16 1.—No change. 2. Seventeen(17)feet in Width. Remainder of section—No change. Amend Sec.8-15-70.Transport permit application process. A.—No change. B. Submittal Requirements.Applicant must submit a complete application form,required submittals,and fee to the Department for review.Required submittals may include,but are not limited to: 1. Route survey and axle configuration drawing. B.2.thru E.—No change. F. Permit Expiration. 1.—No change. 2. Oil Rig Permits expire five(5)days from the date of issuance. Remainder of section—No change. ARTICLE XVI-Vacation of Road Right-of-Way by Board of County Commissioners Amend Sec.8-16-30.Vacations of public road rights-of-way not within historic townsites or subdivisions. A. Complete petitions for vacation of public road rights-of-way not within historic townsites or subdivisions accepted by the Department of Public Works shall include: 1. A complete Petition Application signed by the petitioner with an accurate legal description of the road right-of-way requested to be vacated. 2.and 3.—No change. 4. A list of all adjacent property owners within 500 feet or landowners who are not directly adjacent,but may be affected due to usage of the road right-of-way. A.5.thru B.—No change. C. Within six(6)weeks of the petition being received,and at least ten(10)days prior to the meeting at which the Board of County Commissioners is to consider vacating any public road right-of-way,the Clerk to the Board shall mail notice of the meeting to all persons owning land adjacent to the roadway to be vacated,including any landowner who the PAGE 54 2023-3779 ORD2023-16 Department of Public Works reasonably determines may use the road right-of-way proposed to be vacated to access their property.This notice shall not be required if the public road right-of-way has not been used as a roadway for at least twenty-one(21)years or since it was established. Inadvertent errors by the Department of Public Works in determining who should receive such notice,or by the Clerk to the Board's Office in sending such notice,shall not create a jurisdictional defect in the process,even if such error results in the failure of a property owner to receive such notification. Remainder of section—No change. Amend Sec.8-16-40.Requirements. A.—No change. B. The Board of County Commissioners may approve or deny any request to vacate public road right-of-way as it determines to be in the best interests of the County.The Board may consider any information or evidence it determines appropriate,including,but not limited to,the following,to be provided by the Department of Public Works: 1.—No change. 2. Whether the road right-of-way is a maintained or non-maintained public road,and 3.—No change. 4. Whether there is enough information to determine if the public needs this road right-of-way in the future for items such as utility easements, etc. A title commitment or land survey plat may be required. Remainder of section—No change. Appendix 8-A Reserved—NO CHANGE. Appendix 8-B Road Access Sketches—ATTACHED. Appendix 8-C Cattle Guards—ATTACHED. Appendix 8-D Dust Controls and Seasonal Adjustment Factor—ATTACHED. Appendix 8-E Weld County MS4 Area—ATTACHED. Appendices 8-F—8-J.Reserved—NO CHANGE. Appendix 8-K 1-25 Corridor Plan—ATTACHED. Appendix 8-L Roadside Memorial Sign Application—NO CHANGE. Appendix 8-M Memorial Signs—NO CHANGE. Appendix 8-N Transportation Plan—NO CHANGE. Appendix 8-O Functional Classification Map—NO CHANGE. Appendix 8-P Right-of-Way Use Permit—ATTACHED. Appendix 8-Q Weld County Engineering and Construction Criteria—ATTACHED. BE IT FURTHER ORDAINED by the Board that the Clerk to the Board be,and hereby is, directed to arrange for Municode to supplement the Weld County Code with the amendments contained herein,to coincide with chapters,articles,divisions,sections,and subsections as they PAGE 55 2023-3779 ORD2023-16 currently exist within said Code;and to resolve any inconsistencies regarding capitalization, grammar,and numbering or placement of chapters,articles,divisions,sections,and subsections in said Code. BE IT FURTHER ORDAINED by the Board, if any section, subsection, paragraph, sentence, clause, or phrase of this Ordinance is for any reason held or decided to be unconstitutional,such decision shall not affect the validity of the remaining portions hereof.The Board of County Commissioners hereby declares that it would have enacted this Ordinance in each and every section,subsection,paragraph,sentence,clause,and phrase thereof irrespective of the fact that any one or more sections,subsections, paragraphs,sentences, clauses,or phrases might be declared to be unconstitutional or invalid. The above and foregoing Ordinance Number 2023-16 was,on motion duly made and seconded,adopted by the following vote on the 8th day of January,A.D.,2024. BOARD OF COUNTY COMMISSIONERS WELD COUNTY,COLORADO ATTEST: Mike Freeman,Chair Weld County Clerk to the Board Perry L.Buck,Pro-Tem BY: Deputy Clerk to the Board Scott K.James APPROVED AS TO FORM: Kevin D.Ross County Attorney Lori Saine Date of signature: First Reading: December 4,2023 Publication: December 10,2023,in the Greeley Tribune Second Reading: December 20,2023 Publication: December 24,2023,in the Greeley Tribune Final Reading: January 8,2024 Publication: January 14,2024,in the Greeley Tribune Effective: January 19,2024 PAGE 56 2023-3779 ORD2023-16 1 PAGE OF DOCUMENT INCLUDED IN PAPER FILE . CHAPTER 8 - Public Works APPENDIX 8- B ROAD ACCESS SKETCHES REMAINDE R RETAINED ELECTRONICALLY IN TYLER . DELETE APPENDIX 8- B IN ITS ENTIRETY - RESERVED Weld County, Colorado, Charter and County Code Created : 2023 - 11 -e7 14 : 42 : 52 [ EST ] ( Supp . No . 85 ) Page 1 of 24 CHAPTER 8-Public Works APPENDIX 8-C CATTLE GUARDS AMEND APPENDIX 8-C CATTLE GUARDS Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:52[EST] (Supp.No.85) Page 2 of 24 CHAPTER 8 - Public Works APPENDIX 8-C CATTLE GUARDS fin\. astri . . s: y _ - PUBLIC WORKS DEPARTMENT \)7At - 1111 H STREET, P . O . BOX 758 •-• GREELEY COLORADO 80632 „ ill / / WEBSITE : WWW . CO . WELD . CO . US LtQ -I- Y PHONE : ( 970 ) 304 - 6496 (r FAX : ( 970 ) 304- 6497 CATTLE GUARD INSTALLATION/ RELOCATION REIMBURSEMENT AGREEMENT Date : By signing this document, you have agreed to reimburse Weld County Public Works for materials to install a 16' , 24' , or 32 ' wide Cattle Guard . The Cattle Guard location is on CR between CR/ Hwy and CR/ Hwy at tenths of a mile N , S, E , or W of CR/ Hwy Cattle Guard design shall be in accordance with Weld County specifications and details . Installation will be done by a Weld County Public Works crew at the agreed location . Payment is required prior to installation . A price breakdown : Cattle Guard width Foot : Total $ Landowner( s ) : ( please print) ( signature ) ( please print) ( signature ) Landowner Address : Landowner Phone : Weld County Representative Title * * Sign one copy and send the signed copy with payment to Weld County Public Works at P. O . Box 758, Greeley, Colorado, 80632 Weld County, Colorado, Charter and County Code Created : 2023 - 11 -07 14 : 42 : 52 [ EST ] ( Supp . No . 85 ) Page 3 of 24 CHAPTER 8-Public Works APPENDIX 8-C CATTLE GUARDS CATTLE GUARDS#1 E2 a.' N W t.1 d° ., U 0.� m J I 4--c' I nyK. --Y-,1 D G ii V(AQ W —" O g} a to l CV PW=JQ E -N 0 \ , m Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:52[EST] (Supp.No.85) Page 4 of 24 CHAPTER 8-Public Works APPENDIX 8-C CATTLE GUARDS CATTLE GUARDS#1(cont'd) CONCRETE BASES CROSSBAR ANCHOR AND CLIP . I/4.x 2.STRAP ��- CONNECTING PLATES �rlll�. O \'�\��[f•-W 6x IT STRINGER C)0.20.7 2a7 w x zo.T THREE 13/1"DIA.HOLES CHANNEL 2 1/2. IN EACH END OF BEAM 2 I/2..5 7.;:T 2 CHANNEL LENGTH-9-4- 4 5 5 6 3/8" 8•-O•• 8-O/ 3/8 5-17/8 2-3 3/4 �/ 3-: c LIFTING HOOK TYR t ,COUNTERSUNK I• /4.ANCHOR BOLTS TYPICAL----'.''. I rrPICAL FOR BASE A&C BASE B ALL CONNECTIONS NOTE'OPPOSITE'47°C AND BOLTING PATTERN FOR SECTION A 8 C RESPECTIVELY. Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:52[EST] (Supp.No.85) Page 5 of 24 CHAPTER 8-Public Works APPENDIX 8-C CATTLE GUARDS CATTLE GUARDS#2 -�A I/4•'x 2"STRAP ,—CONCRETE BASE i 1 u4 I CROSSBAR — - -=-- -- CIO z 20.7 CHANNEL -m , !L �1 -� W$s 17 STRINGER 11.A 24.2 PLAN VIEW 9•-4 9 7•-10. 9.. i/2�CL� T�_9•. I 2••� 71/2 iG-G /CROSSBAR '^ ,1 CONERETE BASE A flpi_l_!,......_....,7I/2. /ii1 1 1 f 1 l I 11 7\ f 1 1 1 1 I S l uo.a BARS WITH 'L STRINGER W 8 x IT-y m 4 1�2 r NO.4 ER. J" N� T 4 Y�� NO. SfVRRIPS AT 18:CC WITH I- '6" .I 6-4 i I•-6•• 1 SECTION A-A 2• MIN.THICKNESS M T GAGE 3" CATTLE GUARD DESIGNED DON CARROLL CROSSBAR DETAIL CHECKED OREW"'S'I TING APR OVED WAYNE SMYTH WELD COUNTY ENGINEERIN[ DATE MARCH 31,1981 Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:52[EST] (Supp.No.85) Page 6 of 24 CHAPTER 8-Public Works APPENDIX 8-C CATTLE GUARDS CATTLE GUARDS#2(cont'd) ca �`w = Qi N m i _ a = o I w � w2,1 aaJ, d _ _ wo tVo r w / _ _ � O3e wu WO 'O5- Weld wO J 6 UW �J- Z m O u`J N County,Colorado,Charter and County Code Created:2023-11-07 14:42:52[EST] (Supp.No.85) Page 7 of 24 CHAPTER 8-Public Works APPENDIX 8-C CATTLE GUARDS CATTLE GUARDS#3 6' 3' TYPICAL CROSSBAR CROSSBAROWHRE SRE RAPS >/16 r� 3 /4"z 2 STRAP OR STRINGERS CONTACT N'4 ' • .m ' m � STRINGEP, "r--`—t ter——t 12 5/8" V4" 5/6 2' 2' 2' 2' 2' 2' 12'-0'x 7=9' 12'-0• --CENTER STRINGER SPACING DETAIL SUPER-STRUCTURE GENERAL NOTES, SUPER STRUCTURE TO BE SUPPLIED IN TWO SEPERATE 12'-0"BY 7 9 UNITS.ALL CONCRETE REINFORCING BARS TO BE CONTINUOUS.NO SPLICING OR LAPPING IS ALLOWED. ALL BOLTED CONNECTIONS ARE TO BE DOUBLE NUTTED.ALL ANCHOR BOLTS,NUTS,WASHERS AND CLIPS ARE TO BE GALVANIZED. MATERIALS SHALL MEET THE STATE DEPARTMENT OF HIGHWAYS,DIVISION or HIGHWAYS,STATE OF COLORADO, STANDAND SPECIFICATIONS FOR ROAD AND BRIDGE CONSTRUCTION,199I OF THE FOLLOWING SECTIONS. SEC 509.03 STRUCTURAL CARBON STEEL (ASTM A36) SEC 601.02 CONCRETE (CLASS A) SEC 709.0, REINFORCING STEEL (GRADE 40) Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:52[EST] (Sapp.No.85) Page 8 of 24 CHAPTER 8-Public Works APPENDIX 8-C CATTLE GUARDS CATTLE GUARDS#4 —Ij w 8 x t7 II I DOUBLE NUTTPED ANCHOR CLI DOUBLE WASHER W 8x17 STRINGER 0 0 ' 3/4"¢ANCHOR 80LT5 WITH 4"OF THREAD TYPICAL AT ALL CONNECTIONS. ANCHOR DETAIL 4 vz" r j.:1, _ 3/8`PLATE—.y 13/16"DIA. II HOLE ---10 — ANCHOR CLIP DETAIL 13/16`OM 4 HOLES 3/8.,ATE�,.�.. 0 O 0 14 Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:52[EST] (Supp.No.85) Page 9 of 24 CHAPTER 8-Public Works APPENDIX 8-D DUST CONTROLS AND SEASONAL ADJUSTMENT FACTOR DELETE APPENDIX 8-D IN ITS ENTIRETY-RESERVED Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:53[EST, (Supp.No.85) Page 10 of 24 CHAPTER 8-Public Works APPENDIX 8-E Weld County MS4 Area DELETE APPENDIX 8-E IN ITS ENTIRETY-RESERVED Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:53[Esr] (Supp.No.85) Page 11 of 24 CHAPTER 8-Public Works APPENDIX 8-K DELETE APPENDIX 8-K IN ITS ENTIRETY-RESERVED Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 12 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA APPENDIX 8-P RIGHT-OF-WAY USE PERMIT The intent of the Right-of-Way Use Permit is to regulate and permit the use of Weld County's public right-of- way by private companies,municipalities and/or special districts constructing and burying lines either crossing or running parallel within Weld County right-of-way.Crossings are allowed for all lines.Parallel installations are allowed for lines of"public utilities"that are defined in CRS 40-1-103 and are"domestic or foreign electric light power,gas, or pipeline companies"holding current Certificates of Public Convenience and Necessity issued by the Colorado Public Utilities Commission;for water lines of municipalities,water districts,and water and sewer districts;for transmission lines or pipelines used solely for agricultural purposes;for fresh water above-ground transfer pipelines; for lines in non-maintained right-of-way if approved by Weld County based upon locational factors,such as, surrounding population density,topography,or if the right-of-way provides access to a recorded exemption lot,and with Permittee's agreement to move the line at its sole expense if Weld County or an annexing municipality intends to improve the right-of-way;or if authorized by the Board of County Commissioners in an appeal of the denial of a Right-of-Way Permit application,pursuant to Weld County Code Section 8-13-110.Public right-of-way subject to regulation by the Right-of-Way Use Permit includes Weld County's maintained and non-maintained,and all public drainage easements.A Right-of-Way Use Permit grants the Permittee and its Contractors permission to occupy designated County right-of-way.The Permit authorizes excavation,surveying,and/or construction of facilities within the County right-of-way and provides for their subsequent restoration upon completion of the Project.The Permit is issued solely for the Permittee's and its Contractor's construction of the Project.Permittee is prohibited from changing the use of the Project in any way without first obtaining a new permit. SUBMITTAL REQUIREMENTS 1. Complete application.Permittee must submit a complete Right-of-Way Use Application and include required submittals for review and consideration of its Project.If the Project is approved,a Right-of-Way Use Permit will be issued to the Permittee.It is the Permittee's responsibility to inform its Contractor of all Permit requirements,Provisions,and attached Special Provisions. 2. Drawing,plan set,and map.A drawing,plan set and map are required to be submitted with the Application.Detailed plan(s),sketch,and/or map(s)showing the work location and roadway,edge of roadway,County ROW lines and width,at least one crossroad,and a legend.It is preferred,that drawings be 11x17 or capable of being printed out in 11 x 17.All underground installations must include a cross section drawing showing depth of line being installed per County requirements based on the lowest point of the County ROW and show the County ROW width Engineer stamped plan and profile drawings are required for underground installations running parallel within a roadway.Drawings at intersections must be in plan and profile,and shall be at a scale of 1:100 or as determined by the Department of Public Works. 3. Traffic Control Plan.A Traffic Control Plan(TCP)or Method of Handling Traffic(MHT)must be submitted and approved prior to Permittee's commencement of work.Permittee shall provide all necessary traffic control in accordance with the Manual on Uniform Traffic Control Devices(MUTCD)in drawing form; narratives will not be accepted. (a) Flaggers shall be required at any locations where there is encroachment into a travelling lane. (b) Full road closure requests must be prepared by and signed by a Traffic Control Supervisor(TCS). (c) Full road closures exceeding three(3)days shall require approval of the Board of County Commissioners. 4. Insurance.Permittee and/or its Contractor shall secure and maintain insurance policies and/or provide proof of adequate self-insurance that will protect itself,its sub-contractors,members of the public who Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 13 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA use the right-of-way associated with the Project,and Weld County,Colorado,from claims for bodily injury,death,or property damage which may arise from the construction of the Project,or caused by the facilities which are constructed as permitted herein.The Board of County Commissioners of Weld County,Colorado,its officers,and employees must be named as an"Additional Named Insureds"in all liability insurance policies secured by the Permittee and/or its Contractor.The following insurance policies and amounts are required.Certificates of insurance evidencing such policies shall be delivered to the Weld County Department of Public Works: (a) Statutory Worker's Compensation. (b) Contractor's public liability and property damage in the following sums: Bodily Injury: Property Damage: Each person I$1,000,000 Each accident I$1,000,000 Each accident I$1,000,000 Aggregate I$2,000,000 (c) Automobile public liability and property damage in the following sums: Bodily Injury: Property Damage: Each person I$1,000,000 Each accident $1,000,000 Each accident I$1,000,000 5. Bonding and Surety.If determined necessary by Weld County's Department of Public Works,Permittee shall provide a surety bond or other security for the total amount required to restore the right-of-way under which the Project is to be installed or constructed,based upon current Weld County Department of Public Works contract prices for the performance of such work.Said collateral shall remain in effect for a period of two(2)years after inspection of completed construction by Weld County Department of Public Works.Whether or not covered by a bond,Permittee shall reimburse Weld County for all expenses incurred by it as the result of,or related to,the failure by Permittee or its Contractor to perform all installation,construction,maintenance or other work pursuant to this Permit in a workmanlike manner. 6. Geotechnical Submittals.The Weld County Department of Public Works reserves the right to request from Permittee geotechnical submittals if deemed necessary. The grant of this Permit is conditioned upon Permittee's and its Contractor's compliance with the General Provisions,Construction Provisions,Pipeline Provisions(if applicable),and General Matters set forth below.By accepting this Permit,Permittee and its Contractor agree to comply with the terms and conditions set forth herein. GENERAL PROVISIONS 1. Permit Required. (a) Commencement of construction prior to receiving an approved Permit will result in applicable penalties(see emergency repair section for exclusions listed as item number 12). (b) Contractor must have a copy of this Permit on site during construction of the Project. (c) This Permit requires commencement of construction within three(3)months from date issued unless otherwise stated.The Permittee may apply for an extension if work is not completed before the expiration of three(3)months.All applicable fees must be paid before extension will be issued. 2. Inspection.Inspection of work performed in Weld County right-of-way is required.The Weld County Department of Public Works must be notified 48 hours prior to commencing all work within Weld County Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 14 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA right-of-way.Final inspections are required.Weld County shall have the right to order Permittee or its Contractor to stop work anytime Weld County believes that a violation of this Permit has occurred or if there is a danger to the safety of the public if the work continues. 3. Additional Permits.Permittee shall be responsible for obtaining all other state,federal,or local permits which may be required of Permittee and/or its Contractor to install and/or maintain its Project. Permittee shall provide evidence of such other permits upon request by the Weld County Department of Public Works. 4. Determination of Placement.Weld County reserves the right to determine the specific placement of the Project within its right-of-way. 5. Suspension of Work.Weld County's Department of Public Works shall have the authority to suspend work,wholly or in part,because of the failure of Permittee to properly execute the work in accordance with this Permit.Notwithstanding the issuance of this Permit,Weld County reserves the right to make or to require Permittee to make any changes,additions,repairs or required relocation of any facilities within the dedicated right-of-way at any time. 6. Setback Requirements.By accepting this Permit,Permittee hereby waives its right to require industry setback requirements which it might otherwise require from other utilities which may be placed in Weld County's right-of-way and relinquishes its authority over the placement of all other electric,power,gas, communications or other conduits,pipelines,appurtenances,or irrigation structures which Weld County may allow to be placed in its Right-of-way.Weld County must approve location prior to construction. 7. Compliance with Utility Notification Requirements.Permittee and/or its Contractor shall comply with all applicable requirements of C.R.S.§§9-1.5-101,et seq.,and be responsible for locating all existing utilities and registering all new lines with 811.Contact the Utility Notification Center of Colorado at 811 or 1- 800-922-1987 at least two days in advance of digging.Markers and flags are valid for 30 days.Permittee must remove all utility locates such as flags and marker pins from the right-of-way once the construction is complete.Any subsurface utility engineering notification sent to the Colorado Notification Association shall also be sent to the Weld County Department of Public Works. 8. No Damage to Other Projects.No culverts,irrigation structures,drain lines,utility lines,or any other Projects or facilities within the right-of-way are to be cut or damaged.In the event Permittee or its Contractor damages an existing facility,Permittee shall first notify the owner and either immediately repair and replace the damaged facility or pay the owner to repair and replace the same in accordance with the desires of the owner. 9. Emergencies.Permittee shall report all emergency repairs to Weld County Public Works immediately upon being advised that an emergency exists.During such repairs,Permittee shall utilize proper traffic control measures.Permittee shall apply for a Right-of-Way Use Permit and make the required repairs as soon as practicable after the Weld County Department of Public Works is notified of the emergency situation and the need for such repairs.In no event shall such repairs be completed later than 24 hours after receiving such notification,unless adverse weather conditions prohibit the repair process. 10. Changes Made to the Right-of-way-Permittee's Financial Responsibility.In the event changes are made by Weld County to the right-of-way or appurtenances within the right-of-way that would necessitate removal or relocation of the Project,Permittee shall do so promptly at its own expense upon the request of Weld County. 11. Permittee Responsible for All Project Related Expenses.The construction,operation,maintenance and repair of the Project constructed by Permittee,and all other improvements described in this Permit,shall be at its own expense and without the aid or use of Weld County funds. Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[Esr] (Supp.No.85) Page 15 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA 12. Permittee Solely Responsible.Permittee or its successors and assigns,remains solely responsible for all matters pertaining to the Project and all costs associated with or pertaining to the Project.These responsibilities include,but are not limited to,the following:repair and maintenance of the physical components of the Project;removal of the physical components of the Project upon retirement of the use or following the request of Weld County to remove the Project;cooperation with Weld County and other Permittees whose projects are placed in Weld County's right-of-way. 13. Successors and Assigns of Permittee.It is mutually understood and agreed that this Permit and all the terms and conditions hereof shall extend to and be binding upon the Permittee and its successors,and assigns. CONSTRUCTION PROVISIONS 1. Road Crossings.All underground installations crossing maintained or non-maintained Weld County roadways and road rights-of-way shall be by directional bore unless otherwise approved by Weld County Public Works. 2. Parallel Installations.Parallel installations within the untraveled portion of Weld County road right-of- way may be performed by bore,trenching,plowing,drilling or excavation.Parallel installation methods within the traveled portion shall be determined by the Department of Public Works. 3. Bridge Structures. (a) No lines shall be attached or otherwise placed along or upon any Bridge structure or wing walls. (b) No continuous line shall be installed crossing under a bridge structure. (c) Underground projects installed parallel to a bridge structure must maintain a minimum clearance of five feet(5')from all wing walls and pilings. 4. Minimum Cover for County Road Right-of-Way Installations.All depth requirements are minimums and are subject to approval or modification by the Department of Public Works based on engineering and safety standards and existing utilities in the roadright-of-way.In no event shall any facilities be installed in Weld County road right-of-way at depth less than four feet(4')from top of line measured from the lowest point of the road right-of-way. (a) Dry utilities shall be installed at a minimum depth of four feet(4')from top of line measured from the lowest point of the road right-of-way(flowline). (b) Wet utilities shall be installed at a minimum depth of six feet(6')from top of line measured from the lowest point of the road right-of-way(flowline). (c) All types of oil and gas lines shall be installed at a minimum depth of ten feet(10')from top of line measured from the lowest point of the road right-of-way(flowline).Concrete surfaces shall be crossed at a minimum depth of fifteen feet(15')from top of line measured from the lowest point of the road right-of-way(flowline). (d) All line types crossing non-maintained road right-of-way shall be at a minimum depth of four feet (4')from top of line measured from the lowest point of the road right-of-way(flowline). (e) Culverts must have a minimum of twelve inches(12")of cover. 5. Daily Construction Requirements.At the end of each day during the installation and construction of the Project,Permittee shall observe the following requirements: (a) Working hours allowed under this Permit are from Sunrise to'/hour prior to Sunset. Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 16 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA (b) All materials shall be removed a minimum of ten feet(10')from outside edge of the road shoulder. (c) All excavations upon the traveled portions of the road right-of-way shall be back-filled in accordance with the compaction requirements set forth below unless otherwise approved by Weld County. (d) All traffic signs must be in place per the approved Traffic Control Plan or removed or covered if not applicable to nightly activities. 6. Equipment Movement and Equipment Crossings. (a) Movement of cleated or track equipment is restricted to the immediate work area.Equipment shall be transported to a proper unloading area.No cleated or track equipment may work on or move over any road way surface without mats. (b) Equipment crossings shall require a separate permit and must meet safety and sight distance criteria for approval.Crossings are in line with the Project and shall be built up level with the road surface with a practicable anti-tracking material to prevent damage to the road surfaces and shoulder areas.Crushed concrete is prohibited for use as a surface material.A minimum of a twelve-inch(12")culvert shall be placed in ditch areas under tracking pad to maintain proper drainage.Existing ditch and upstream and downstream culverts must be observed in determining appropriate drainage culvert size. 7. Site Markers.Permittee shall mark the site of the construction of the Project,whether permanent or temporary,with markers acceptable to Weld County Department of Public Works.Markers shall be placed as far from edge of road as to not interfere with normal road maintenance. 8. Future Line Location.The installation of non-ferrous lines in the road right-of-way shall require a suitable means to facilitate future line location such as,but not limited to,metallic warning tape installed above the line and registration with 811. 9. Concrete Surfaces.There is a strict no cut policy on all concrete surfaces,which includes potholing.Any damage or cutting of concrete surfaces will result in the Permittee being responsible for the cost of a full replacement of concrete panel(s)by a Contractor approved by Weld County.Bore grout may be required for underground crossings of concrete surfaces. 10. Asphalt Surfaces.Asphalt surfaces are not to be cut unless approved by the Weld County Department of Public Works.If an asphalt surface cut is granted,the cut shall be repaired with a flowable fill cement (refer to Section 11.Compaction Requirements,below)and hot bituminous pavement and/or concrete placed at a thickness of existing plus one(+1). 11. Compaction Requirements. (a) All compaction of backfills and road surfaces shall be compacted in accordance with the most current versions of the Colorado Department of Transportation(CDOT)Standard Specifications for Road and Bridge Construction and Field Materials Manual. (b) All backfills located within an existing asphalt surface or under the asphalt not currently in place but will be as part of a new road construction,must be compacted using flow-fill cement in the upper three feet(3')of backfill. (c) If any wet or non-compactable materials are produced from excavations,they shall be completely removed from the road right-of-way and replaced with compactable materials.The road right-of- way shall then be returned to the original grades and cross sections.Weld County Department of Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST, (Supp.No.85) Page 17 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA Public Works shall have the authority to determine what materials shall be discarded and what materials shall be acceptable as replacement. (d) On gravel roads where excavation materials are stacked on the road surface,road base of 1.5 inch surface gravel as specified in Chapter 9 of the Weld County Engineering and Construction Criteria Manual(Appendix 8-Q)specifications for surface gravel shall be spread over the entire road surface at a minimum depth of six inches(6")upon completion of the work.Shoulders on paved roads or barrow ditches where excavation is done shall require a minimum of four inches(4")of 3/4-inch Class 6 aggregate road base material.Recycled Concrete will not be substituted for Class 6 aggregate road base.These amounts are minimums and do not supersede any requirements within the Permit. (e) On gravel roads where excavation is done within the roadway,backfilling lifts greater than eight inches(8"),but not exceeding twelve inches(12"),shall be permitted providing that Permittee has suitable equipment to properly compact the depth of lift placed.Weld County Public Works shall determine if Permittee's equipment and the depth of backfill lift is appropriate.Ninety-five percent (95%)of a standard proctor shall be required at any trench depth or in replacement of any materials within the traveled portion of the road right-of-way.Eighty-five percent(85%)of a standard proctor shall be required at any trench depth or in replacement of any materials off the traveled portions of the road right-of-way.Installations running parallel within a gravel roadway will require a final placement of a minimum of six inches(6")of surface gravel after all of the Project has been placed and compaction test results are in compliance. (f) Potholes in gravel surfaces shall be filled completely with road base and compacted.Potholes in asphalt shall be filled with a cement/grout to existing thickness plus 1(+1)or filled with a compactable base material and the final placement a HMA or concrete material of existing thickness plus one(+1).Cold patching material is not an acceptable method of restoration. 12. Reseeding.Permittee shall reseed,with a seed mix approved by Weld County Department of Public Works,all areas within the road right-of-way in which vegetation was removed or disturbed during the installation of its Project. 13. Points of Access.Permittee shall install manholes and other points of access to underground lines within the boundaries of the road right-of-way outside the normal wheel path of the roadway so that they do not obstruct maintenance operations within the road right-of-way.Permittee shall,at its sole expense, adjust access points,when requested to do so by Weld County. 14. Survey Monuments.Permittee or its Contractor shall preserve or replace all survey monuments or benchmarks at each work site.If such monuments or bench marks are destroyed,Permittee shall hire a registered land surveyor to replace destroyed monuments or bench marks.If Permittee chooses to preserve such monuments or benchmarks,it shall also hire a registered land surveyor to complete such preservation. 15. Permittee's Obligations Regarding Surveys. (a) All surveying performed within the boundaries of the road right-of-way shall be conducted with proper safety equipment and advanced warning signs; (b) Surveying permit holders can be issued an annual permit. (c) Any excavation within the boundaries of the road right-of-way will be backfilled with the same material or better than what was excavated. Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST, (Supp.No.85) Page 18 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA (d) Weld County Department of Public Works offers free monument boxes and lids to Permittee to establish,upgrade or perpetuate the location of an aliquot corner of any section on a paved road. Permittee shall furnish the location of the section corners being preserved to the Department of Public Works when obtaining monument boxes. 16. Permittee's Obligations Regarding the Completion of Project. (a) Permittee shall place surface gravel,as specified in Chapter 7 of the Weld County Engineering and Construction Criteria,on all surfaces where any damage has occurred to the road surface from equipment,trenching,or storage of material.Weld County shall determine the damaged areas, remedial work required,and timing of said work. (b) Permittee shall complete road restoration including,but not limited to,clean-up(including utility markers),repair of damaged facilities,trench compaction,and replacement of gravel shall be kept within one(1)mile of new excavation. (c) All disturbed portions of the road right-of-way or damaged road surfaces are to be returned to their original condition prior to demobilizing.If the road right-of-way is not returned to original conditions,Weld County may perform or contract such remedial work and Permittee shall pay for all work or forfeit its surety bond in order to pay for all work done. (d) Permittee shall own,maintain,operate and repair any line installed or constructed herein in accordance with the regulations,conditions and terms of this permit.No lines installed within County rights-of-way may be abandoned by the owner at any time.Although the lines may be retired,they may not be abandoned and all responsibility for such lines remains with the owner. The County does not recognize,nor accept,any lines designated by any other source as abandoned,and the County will continue to expect such lines to be maintained or removed by the Permittee. 17. Line Retirement.Retirement of lines in Weld County road right-of-way are still required to be located as part of 811.If Weld County approves a line to be retired,the retirement of an existing line in the road right-of-way shall be subject to conditions as determined by the Weld County Department of Public Works based on the age,condition,material type,and size.Permittee shall cut,cap,and fill lines that are not required to be removed. 18. Line Abandonment.If Permittee desires to abandon a line from being located as part of 811 notification, Permittee shall completely remove the line from Weld County road right-of-way,unless otherwise approved by Weld County. 19. Drainage Interference.Permittee shall not obstruct the natural free and clear passage of water along the roadside ditch flow lines or other waterways.If surface drainage is to be affected,Permittee is responsible for the proper disposition of the runoff. PIPELINE PROVISIONS 1. Natural Gas/Crude Oil Pipelines. (a) Road crossings for natural gas/crude oil pipelines must be by directional bore,only. (b) Above-ground appurtenances and/or equipment are not permissible for installation within the County road right-of-way and must comply with setback requirements. 2. Permanent Fresh Water(Non-Potable)Pipelines. (a) Road crossings for permanent fresh water(non-potable)pipelines must be by directional bore, only. Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 19 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA (b) Permanent fresh water(non-potable)pipelines must extend past future road right-of-way prior to daylighting. (c) Above ground appurtenances and/or equipment are not permissible for installation within the County road right-of-way and must comply with setback requirements. (d) Weld County approval is required for any change of use or retirement of a permanent fresh water (non-potable)pipeline. 3. Temporary Above-Ground Transfer Pipelines. (a) Above-ground transfer pipelines are allowed as a temporary use for a period of 6 months or less for both road crossings and parallel installations.See the limitations and restrictions set forth below depending upon crossing methods. (b) Above-ground transfer pipelines may transfer fresh or recycled water and dairy irrigation slurry, only. (c) The source of water must be disclosed on the Right-of-Way Use Application and location maps. (d) The use of non-maintained Weld County road right-of-way for temporary above-ground transfer pipelines shall be negotiated with the landowner(s). (e) Existing driveway culverts may not be used for water transfers and permission from property owner must be provided for crossing private driveways or accesses. (f) All pipelines or lay flat pipes occupying the road right-of-way(running parallel to the roadway) must be secured up out of the ditch flowlines and away from the road edges.They may not interfere with normal road maintenance or impede drainage.All accesses and driveways shall be accessible and cannot be blocked by lay flat lines. Trailer mounted pumps shall be placed on private property and must be maintained and re-fueled on private property. Crossing methods for temporary above-ground transfer pipelines: 1) Plate/Manifold: a. Applicable for untreated gravel roadways for a transfer duration of 10 days or less. b. Must be covered with 11/2"surface gravel with a minimum of 15-foot road base tapers on each side.All forms of traffic must be able to safely cross the plate/manifold. c. Traffic control signs required including a speed reduction to 15 mph for the duration of the transfer. d. Permittee is required to maintain the crossing which includes 24-hour snow removal in winter. 2) Culvert Sleeve: a. Applicable for longer term transfers crossing untreated gravel roadways only. b. Maximum culvert size is an 18"outside diameter for a single line transfer and 24"outside diameter Elliptical for a double line transfer unless approved by the Weld County Department of Public Works. c. Minimum of 18"of 1.5"surface gravel cover on culvert. Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 20 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA d. Compaction tests of road base is required after culvert is removed if flowable fill is not used for final restoration of the roadway. 3) Existing Culverts: a. Requests for use of existing County culverts(any culvert crossing under a County maintained roadway or intersection)are subject to special review.Use is for a maximum of 15 days. b. Existing culverts are not available for use from March through October. c. Driveway/access culverts are not available for use. d. If the culvert also serves for irrigation,written permission from the Irrigation or Ditch Company may be required. e. Culvert must be cleared anytime drainage is impeded due to run-off or flooding or a significant rain or flooding event is forecasted. Shut off valves should be placed on each side of culvert to allow for disconnection and removal. 4) HDPE or PVC Pipe: a. Applicable for longer term transfers where a paved,hard surface,or treated gravel roadway must be crossed. b. Pipeline installation is required to be at a depth of 10 feet based on the lowest point in the County ROW and ends must extend past future road right-of-way before daylighting.Installation method by boring only. c. Weld County approval is required for any change of use or retirement of the pipeline. 4. Produced Raw Water Pipelines. (a) No temporary above-ground transfers. (b) Pipelines will only be considered for approval that are transferring to a State and County approved injection or recycling facility. (c) Casing is required for crossing under County roadways. (d) Casing type may be determined by the Permittee or its Contractor. (e) Casing maximum outside diameter is not to exceed 12". (f) Casing ends must extend outside of the County road right-of-way. (g) If Flex Steel Pipe or equivalent with a temperature rating of 180 degrees or higher is used,casing requirement will be waived. (h) Maximum size of the produced water pipeline is not to exceed 8"and not to exceed 10"outside diameter(OD). (i) Requests for larger diameter pipelines will require special review by the Weld County Department of Public Works. (j) Location markers shall be green in color and must list"produced water"and an emergency contact number. GENERAL MATTERS Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 21 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA 1. Terms. (a) All references herein to"Right-of-Way"refer to a portion of land that is dedicated or granted to and accepted by Weld County for transportation purposes,such as a paved or gravel roadway or highway whether maintained or unmaintained by Weld County.The term is used as both singular and plural. (b) All references herein to"Permittee"are to any persons and/or entities applying for and being issued this Right-of-Way Use Permit granting permission to construct their Project within Weld County's right-of-way. (c) All references here to"Lines"means all underground and overhead cable,telephone,electric, power,wire,gas and irrigation lines,and/or appurtenances,structures or pipelines. (d) All references herein to"Contractor"are to any persons or business entities retained by Permittee to install the Project in Weld County right-of-way. (e) All references herein to"Permit"refer to this Right-of-Way Use Permit,including all Permit requirements,Provisions,and attached Special Provisions. 2. Weld County's Limited Interest in Right-of-Way.Weld County owns a limited interest in the right-of-way and therefore,does not,by the issuance of this Permit,warrant its ownership of the right-of-way. Permittee is responsible for determining the ownership of properties traversed by its lines,the location of all property boundary lines,and the ownership of all right-of-way.Therefore,Permittee shall obtain from the fee title owner(s)of the right-of-way or others having proprietary interests in the right-of-way such authority or rights as Permittee may need,in addition to this Permit for Permittee's use of the right- of-way.Permittee acknowledges and agrees that the authorization granted herein by Weld County is subject to Permittee's securing such authority or rights. 3. Rights Reserved by Weld County.Permittee acknowledges and agrees that the Right-of-Way which are the subject of this Permit exist as public right-of-way for the primary benefit of the travelling public,and that the rights granted in this Permit to the Permittee are subject to Weld County's rights and obligations to preserve and maintain the right-of-way and the public's right to continue to travel safely upon the right-of-way. (a) Subject to the right granted herein to Permittee,Weld County reserves the remaining use of the Right-of-Way for existing and future construction,operation,maintenance,repair,replacement relocation and abandonment of its own use and facilities. (b) Weld County reserves the right to revoke this Permit at any time if Permittee or its Contractor fails to comply with the requirements of this Permit.Should this Permit be terminated for non- compliance by Permittee or its Contractor,any lines or facilities installed prior to the termination shall remain the responsibility of the Permittee and may be removed or maintained by Permittee at the sole discretion of Weld County. (c) This Permit is non-exclusive.Weld County reserves the right to allow other public and private utilities and entities to utilize the subject right-of-way and may impose location requirements and restrictions on Permittee in anticipation of requests by future public and private utilities and entities to occupy the right-of-way. (d) Weld County reserves the right to reconstruct,widen and/or maintain the right-of-way which are the subject Permit.In the event this work requires Permittee to incur expenses to preserve,re- locate or maintain its Project,Permittee shall do so upon notification from Weld County at its sole cost. Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 22 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA 4. Indemnification.Except for the negligence of Weld County,Permittee shall indemnify and save harmless Weld County,its officers,employees,agents,successors and assigns from any damage or loss sustained by them or any of them,which arises by reason of Permittee's negligence with respect to the installation, upgrade and/or maintenance of the Project. 5. Hold Harmless.Permittee agrees to protect Weld County and save and hold Weld County harmless from any and all third party claims and damages which the installation and/or maintenance of Permittee's Project and related facilities may directly or indirectly cause.Additionally,Permittee releases Weld County from any and all claims and damages to property owned by Permittee resulting from any act, either by or on the part of Weld County or by or on the part of any third-party. 6. No Assignment.Permittee shall not assign any or all of its rights under this Permit without first obtaining written consent to such assignment from Weld County,which consent shall not be unreasonably withheld.However,in the event Permittee contracts with a third-party Contractor to perform the work associated with the installation of the Project,Permittee remains solely responsible for Contractor's compliance with the terms and conditions of this Permit. 7. Entire Permit Agreement.The parties hereby agree that neither has made or authorized any agreement with respect to the subject matter of this instrument other than expressly set forth herein,and no oral representation,promise,or consideration different from the terms herein contained shall be binding on either party hereto,or its agents or employees.This Permit embodies all agreements between the parties hereto and there are no promises,terms,conditions,or obligations referring to the subject matter whereof other than as contained herein. 8. Effect of Invalidity of Provision.If any term or provision of this Permit,or the application thereof to any person or circumstances shall,to any extent,be held invalid or unenforceable,the remainder of this Permit,or the application of such terms or provisions,to a person or circumstances other than those as to which it is held invalid or unenforceable,shall not be affected,and every other term and provision of this Permit shall be deemed valid and enforceable to the extent permitted by law. 9. No Waiver of Immunity.No term or condition of this Permit shall be construed or interpreted as a waiver, express or implied,of any of the immunities,rights,benefits,protections or other provisions,of the Colorado Governmental Immunity Act§§24-10-101 et seq.,as applicable now or hereafter amended. 10. No Third Party Beneficiary.It is expressly understood and agreed that the enforcement of the terms and conditions of this Permit,and all rights of action relating to such enforcement,shall be strictly reserved to Weld County and nothing in this Permit shall give or allow any claim or right of action whatsoever by any other person not included in this Permit.It is mutually understood and agreed that this Permit and all the terms and conditions hereof shall extend to and be binding upon the Permittee and its successors, and assigns. SPECIAL PROVISIONS This Permit may be subject to additional Special Provisions.Such Special Provisions are attached hereto. Permittee Signature: Printed name: Date: Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 23 of 24 CHAPTER 8-Public Works APPENDIX 8-P RIGHT-OF-WAY USE PERMITA AMEND APPENDIX 8-Q WELD COUNTY ENGINEERING AND CONSTRUCTION CRITERIA 2020-weld-cou my-engi neeri ng-and-construction-criteria-fi nal-version-2021-03-17.pdf Weld County,Colorado,Charter and County Code Created:2023-11-07 14:42:54[EST] (Supp.No.85) Page 24 of 24 APPENDIX 8-Q WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA This page intentionally left blank. TABLE OF CONTENTS Chapter 1 General Provisions 1 1.1 Title 1 1.2 Purpose and Background 1 1.3 Applicability 1 1.4 Reference Documents 1 1.5 Interpretation 2 1.6 Road Acceptance 2 1.7 Improvements Agreements 3 Chapter 2 Road Classifications and Typical Sections 4 2.1 Road Classification System 4 2.1.1 Functional Classifications 4 2.1.2 Primary vs Secondary Classifications 5 2.2 Right-of-Way Widths 5 2.3 Right-of-Way Use Permit 5 2.4 Right-of-Way Determination 5 2.5 Right-of-Way Acquisitions 6 2.6 Typical Cross-Sections 6 Chapter 3 Surveying 17 3.1 Survey Data-17 3.2 State Plane 17 3.3 Monument Boxes 17 3.4 Road Safety 17 Chapter 4 Roadway Design Criteria 18 4.1 General 18 4.1.1 Policy on the Use of Referenced Publications 18 4.1.2 Typical Plan Set Guidelines 18 4.1.3 Design Speed 21 4.2 Horizontal Alignment 22 4.2.1 Horizontal Curves 22 4.2.2 Superelevation 23 4.2.3 Transitions 23 4.2.4 Cross Slope 24 4.3 Vertical Alignment 24 4.3.1 Maximum and Minimum Grades 24 4.4 Sight Distance 25 4.4.1 Stopping Sight Distance 25 4.4.2 Passing Sight Distance 27 4.4.3 Decision Sight Distance 27 4.4.4 Intersection Sight Distance 28 4.5 Intersections 29 4.5.1 Alignment and Profile 29 WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE Ii 4.5.2 Corner Radii 30 4.5.3 Approval Requirements 30 4.5.4 Auxiliary Lanes 31 4.6 Cul-de-Sacs 31 4.7 Bridges 31 4.7.1 Bridge Hydraulic Capacity 31 4.7.2 Freeboard 32 4.7.3 Bridge Scour 33 4.7.4 Use of HEC-RAS 33 4.7.5 Bridge Railing 33 4.7.6 Minimum Structural Requirements 33 Chapter 5 Drainage Criteria 34 5.1 General 34 5.2 Drainage Law 35 5.3 Drainage Policy 35 5.3.1 Submittal Requirements 35 5.3.2 Data Collection 37 5.4 Rainfall 37 5.5 Runoff 38 5.5.1 The Rational Method 39 5.5.2 Larger Basin Rainfall Methods 45 5.6 Roads,Inlets,and Storm Drains 45 5.6.1 Applicable Software 45 5.6.2 Roadway Drainage 45 5.6.3 Inlets 46 5.6.4 Pipes 46 5.6.5 Manholes 47 5.7 Open Channels,Roadside Ditches,and Grass Swales 48 5.7.1 Applicable Software 48 5.7.2 Open Channels and Swales 48 5.7.3 Roadside Ditches 52 5.8 Culverts 53 5.8.1 Applicable Software 53 5.8.2 Sizing 53 5.8.3 Materials 54 5.8.4 Cover 54 5.8.5 End Sections and Safety Grate 54 5.8.6 Maintenance 55 5.9 Riprap 55 5.10 Storage 62 5.10.1 Retention 62 5.10.2 Detention 63 5.10.3 Dam Information 73 5.10.4 Irrigation Ditches/Private Irrigation Systems 74 WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE Iii 5.11 Stormwater Drainage Criteria Variances 75 5.12 Oil and Gas Stormwater Management 76 Chapter 6 GRADING and MS4 Requirements 78 6.1 Erosion Control&Grading Requirements 78 6.1.1 Applicability 78 6.1.2 Grading and Erosion Control Plans 78 6.1.3 Implementation 79 6.1.4 Grading Permit Deadline(Fee)&Extension 79 6.1.5 Tracking Control 79 6.2 MS4 Requirements 82 6.2.1 Designated MS4 Areas and Responsibilities 82 6.2.2 Applicability of MS4 Requirements 83 6.2.3 Required Permits 83 6.2.4 MS4 Requirements for Pre-Construction 84 6.2.5 MS4 Requirements for Construction Activity 86 6.2.6 MS4 Requirements for Post Construction 87 6.2.7 MS4 Requirements for As-Built Drawing Checklist 91 6.3 Revegetation 91 6.3.1 Site Preparation 91 6.3.2 Seeding and Planting 92 6.3.3 Mulching 92 6.3.4 Maintenance 92 6.3.5 Erosion Protection Design Criteria 93 Chapter 7 FEMA Floodplain Requirements 94 7.1 Background Information 94 7.2 Floodplain Management Obligations 94 7.3 FEMA Floodplains 94 7.3.1 Floodplain Requirements 94 Chapter 8 Traffic Criteria 96 8.1 Traffic Impact Studies 96 8.1.1 Traffic Impact Study Area 96 8.1.2 Preliminary Traffic Impact Analysis 96 8.1.3 Traffic Impact Study Requirements 97 8.1.4 Traffic Impact Study Checklist 101 8.1.5 Updating Existing Traffic Impact Studies 101 8.2 Change in Access Use 103 8.3 Temporary Access 103 8.4 Traffic Control Devices and Plans 103 8.4.1 Signage and Striping Plans 103 8.4.2 Striping guidance 104 8.4.3 Type and Location of Signs 104 8.4.4 New Roadway Signage 104 8.4.5 Memorial Sign Applications 104 WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE (iii 8.4.6 Construction Criteria 105 8.5 Access Points 105 8.5.1 Local Roadways 105 8.5.2 Collector Roadways 106 8.5.3 Arterial Roadways 106 8.5.4 State Highway and Interstate Systems 106 8.5.5 Shared Accesses 106 8.5.6 Restricted Movement Access 107 8.5.7 Access Control Plans 107 8.6 Access Design 107 8.6.1 Geometric Design 107 8.6.2 Access Sight Distance 108 8.6.3 Subdivision Roads Sight Distance 109 8.7 Auxiliary Turn Lanes 110 8.7.1 Auxiliary Lane Length 112 8.7.2 Storage Lengths 113 8.7.3 Auxiliary Lane Conflicts 114 8.8 Access Construction 114 8.8.1 Gravel Requirements 114 8.8.2 Pavement Requirements 115 8.8.3 Access Drainage 115 8.8.4 Structures 115 8.9 Average Daily Traffic Count 115 8.9.1 Vehicle Classification 116 Chapter 9 Soil Investigation and Pavement Design 118 9.1 Introduction and Purpose 118 9.2 Field Investigation and Soil Samples 118 9.2.1 Testing Frequency 118 9.2.2 Sampling Procedures 118 9.3 Subgrade Testing 118 9.3.1 Classification 118 9.3.2 Swell Test 119 9.3.3 pH and Sulfate 119 9.3.4 Moisture Density 119 9.3.5 Hveem Stabilometer 119 9.4 Pavement Design Criteria for Onsite Roadways 119 9.4.1 Design Equivalent Single Axle Loads(ESAL) 120 9.4.2 Traffic Growth Rate 120 9.4.3 Lane Factor 120 9.5 Flexible Pavement Design 121 9.5.1 Serviceability and Reliability 121 9.5.2 Standard Deviation 121 9.5.3 Drainage Factor 121 9.5.4 Strength Coefficients 122 WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE liv 9.5.5 Pavement Thickness 122 9.5.6 Pavement Design 122 9.6 Material Specification 122 9.6.1 General 122 9.6.2 Procedure for Material Source Approval 123 9.6.3 Hot Mix Asphalt 123 9.6.4 Portland Cement Concrete Pavement 124 9.6.5 Aggregate Base Course 125 9.6.6 Aggregate Surface Course(Gravel) 126 9.7 Soils/Pavement Design Report 127 Chapter 10 Construction Criteria 129 10.1 General 129 10.1.1 Policy on the Use of Referenced Publications 129 10.1.2 Control of Work and Inspection 129 10.1.3 Project Acceptance and Warranty 130 10.2 Contractor Responsibilities 130 10.2.1 Qualifications,Insurance Requirements,and Licensing 130 10.2.2 Pre-Construction Meetings 131 10.2.3 Permits 131 10.2.4 Public and Worker Safety 131 10.2.5 Utility Coordination 132 10.2.6 Dust Control 132 10.2.7 Traffic Control 133 10.2.8 Removal of Unacceptable or Unauthorized Work 133 10.2.9 Record Drawings and Record Keeping 134 10.3 Materials Quality Control and Testing 135 10.3.1 Qualifications of Testing Personnel and Laboratories 135 10.3.2 Minimum Testing Types and Frequencies 135 10.3.3 Material Sources and Sampling 135 10.3.4 Required Submittals 136 10.3.5 Soils Reports and Pavement Designs 136 10.3.6 Materials Rejection 136 10.4 Excavation and Embankment 137 10.4.1 Utility Trenching and Backfill Requirements 137 10.4.2 Unsuitable Materials 137 10.4.3 Moisture and Density Control 137 10.5 Subgrade Construction Methods 138 10.5.1 Unsuitable Materials 138 10.5.2 Soft Spots 138 10.5.3 Moisture and Density Control 138 10.5.4 Subgrade Proof Rolling 138 10.5.5 Treated Subgrades 139 10.6 Base Course Construction Methods 139 10.6.1 Gradation and Moisture and Density Control 139 WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE )v 10.6.2 Base Course Proof Rolling 140 10.6.3 Treated Base Courses 140 10.6.4 Acceptance Prior to Paving 141 10.7 Pavement Construction Methods 141 10.7.1 Pre-Paving Meetings 141 10.7.2 Recycled Asphalt Pavement Surfaces 141 10.7.3 Hot Mix Asphalt Surfaces 141 10.7.4 Concrete(PCCP)Surfaces 142 10.7.5 Pavement Cut and Patching Requirements 145 10.8 Structures and Drainage Features 146 10.8.1 Bridges 146 10.8.2 Culvert and Pipe Installation 146 10.8.3 Curbs,Gutters,and 146 10.8.4 Concrete Structures,Manholes,and Inlets 147 10.8.5 Retaining Walls and Slope Stabilization Measures 147 10.9 Other Roadway Features 147 10.9.1 Pavement Markings 147 10.9.2 Traffic Control Devices(Signs and Signals) 147 10.9.3 Trees and Plantings 148 10.9.4 Sidewalks and Trails 148 10.9.5 Guardrails 148 10.9.6 Fences 148 10.9.7 Cattle Guards 149 Chapter 11 Permitting 150 11.1 Transport Permit 150 11.2 Right-of-Way Use Permit 150 11.3 Access Permit 150 11.4 Grading Permit 150 11.5 Floodplain Development Permit 151 Chapter 12 Variance Requests 152 LIST OF FIGURES Figure 2-1 Rural Local and Collector Roads(Unpaved)(Interim) 9 Figure 2-2 Rural Local(Ultimate) 10 Figure 2-3 Rural Collector(Paved) 11 Figure 2-4 Rural Arterial 12 Figure 2-5 County Highway 13 Figure 2-6 Urban Local 14 Figure 2-7 Urban Collector 15 Figure 2-8 Urban Arterial 16 Figure 4-1 Horizontal Curve 22 Figure 4-2 Minimum Tangent from Intersection 23 WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE (vi Figure 4-3 Intersection Cross Slope Detail 24 Figure 4-4 Horizontal Sight Distance 26 Figure 4-5 Crest Vertical Curve 27 Figure 4-6 Departure Sight Triangles at Intersection(Stop Control) 29 Figure 4-7 Typical Intersections 30 Figure 5-1 Weld County Watersheds 35 Figure 5-2 Manning's n vs.Depth for Low-Flow Section in a Composite Channel 51 Figure 5-3 Manning's n vs.VR for Two-Retardances in Grass-Lines Channels 52 Figure 5-4 Riprap Apron Detail for Culverts In Line with the Channel(USDCM,Vol 2 Figure 9-34) 57 Figure 5-5 Expansion Factor for Circular Conduits(USDCM,Vol 2 Figure 9-35) 58 Figure 5-6 Expansion Factor for Rectangular Conduits(USDCM,Vol 2 Fig 9-36) 59 Figure 5-7 Riprap Erosion Protection at Circular Conduit(Valid for Q/D2.5<6.0)(USDCM, Vol 2 Figure 9-38) 60 Figure 5-8 Riprap Erosion Protection at Rectangular Conduit Outlet(Valid for Q/WH1.5<8.0) (USDCM,Vol 2 Figure 9-39) 61 Figure 5-9 Water Quality Capture Volume(WQCV)Based on BMP Drain Time(USDCM, Vol 3 Fig 3-1) 66 Figure 5-10 Outlet Structure Plan and Profile Example 69 Figure 5-11 Emergency Spillway Typical Design 71 Figure 8-1 Access Approach 108 Figure 8-2 Departure Sight Triangles at Access(Stop Control) 109 Figure 8-3 Subdivision Road Sight Distance Triangle 109 Figure 8-4 Auxiliary Lanes Layout 110 Figure 8-5 Geometric Components of A Deceleration Lane 111 Figure 8-6 Geometric Components of an Acceleration Lane 112 Figure 8-7 Tracking Control for Temporary Accesses Error!Bookmark not defined. Figure 9-1 FHWA Vehicle Classification(CDOT M-E Pavement Design Manual,Figure 3.6) Error! Bookmark not defined. LIST OF TABLES Table 2-1 Typical Cross Sections Summary(Rural) 7 Table 2-2 Typical Cross Sections Summary(Urban) 8 Table 4-1 Roadway Design Criteria 21 Table 4-2 Stopping and Passing Sight Distances and K Values 26 Table 4-3 Decision Sight Distance 28 Table 4-4 Design Frequencies 32 Table 5-1 Runoff Coefficient Equations for Weld County/2008 MHFD(HSG-a) 39 Table 5-2 Percentage Impervious Values for Weld County 40 Table 5-3 Runoff Coefficient Equations for Weld County/2007 MHFD(HSG-A) 41 Table 5-4 Runoff Coefficient Equations for Weld County/2007 MHFD(HSG-B) 42 Table 5-5 Runoff Coefficient Equations for Weld County/2007 MHFD(HSG C/D) 43 Table 5-6 NRCS Conveyance Factor,K 44 Table 5-7 Inlets for Weld County 46 WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE I vii Table 5-8 Theoretical Capacity of Inlets for Weld County 46 Table 5-9 Manhole Sizes 47 Table 5-10 Roughness Coefficients("n")for Channel Design(After Chow 1959) 50 Table 5-11 Trapezoidal Channel Design Guidance/Criteria 52 Table 5-12 Maximum HW/D Requirements for Weld County 54 Table 5-13 Classification and Gradation of Ordinary Riprap 62 Table 5-14 Drain Time Coefficients for WQCV Calculations 66 Table 5-15 WQCV Outlets Orifice Plate Perforation Sizing 67 Table 5-16 Non-Jurisdictional vs Jurisdictional Dam Criteria Summary 73 Table 8-1 Updating on Existing TIS 103 Table 8-2 Minimum Access Spacing Criteria(feet) 105 Table 8-3 Access Geometry 107 Table 8-4 Auxiliary Lane Requirements 111 Table 8-5 Components of Speed Change Lane Lengths for Rural Highways(R-B)from State Highway Access Code 113 Table 8-6 Acceleration/Deceleration Lane and Taper Design Criteria and Redirect Taper for Through Lanes 113 Table 8-7 Grade Adjustment Factors for Acceleration Lanes 113 Table 8-8 Auxiliary Lane Storage Lengths 114 Table 9-1 Test Requirement and Frequency 119 Table 9-2 Test Requirement and Frequency Error!Bookmark not defined. Table 9-3 Equivalence Load Factors(CDOT Pavement Design Manual,Table H.2) 120 Table 9-4 Lane Factors(Modified from CDOT Pavement Design Manual,Table 3.3) 120 Table 9-5 Serviceability 121 Table 9-6 Reliability Factor 121 Table 9-7 Drainage Factor 121 Table 9-8 Strength Coefficient 122 Table 9-9 Master Range Table for Hot Mix Asphalt from Table 703-4 in CDOT's Standard Specifications for Road and Bridge Construction 124 Table 9-10 Concrete Aggregate Gradation Table from Table 703-1 in CDOT's Standard Specifications for Road and Bridge Construction 125 Table 9-11 Aggregate Base Course Requirements 126 Table 9-12 Aggregate Surface Course Requirements 127 Table 10-1 Pavement Marking Types on Concrete 143 LIST OF APPENDICES Appendix A Weld County Drainage Basin Map Appendix B Drainage Report Checklist Appendix C CDOT Operations and Maintenance Plan Guidelines Appendix D As-Built Drawing Checklist Appendix E USDCM 2007 Runoff Coefficients Appendix F Rational Formula-Based Modified FAA Procedure Appendix G Grading Permit Checklist WELD COUNTY ENGINEERING 8z CONSTRUCTION CRITERIA PAGE (viii Appendix H MS4 Pollution Prevention Plan Checklist and Manual Appendix I Traffic Impact Study Checklist Appendix J Weld County Standard Details WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE lix This page intentionally left blank. WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE Ix CHAP TER 1 GENERAL PRO VISIONS 1 . 1 TITLE This manual is called the Weld County Engineering & Construction Criteria and will be referred to throughout the text as the WCECC . 1 . 2 PURPOSE AND BACKGROUND Communities and counties often provide engineering criteria for the repair and construction of infrastructure , outlining specific " must build " requirements . In Weld County, Colorado , which covers 4, 000 square miles, the range of soil types and site conditions is so varied that it is not practical or advisable to develop specific requirements . In Weld County, one size does not fit all . However, recognizing the need in the engineering community for basic information about the County' s criteria for acceptable infrastructure , the County has developed this document . It outlines design and material options and guidelines for the design , construction , location , improvement, and maintenance of infrastructure in Weld County . The criteria outlined in this manual are intended to provide the designer with guidance to facilitate the development of infrastructure that is well suited to County needs and is safe , efficient, and economical . Some cases may arise where conformance to these criteria will be exceptionally difficult . In such cases, requests for variance to these criteria will be considered on a case - by-case basis . The overriding requirement is that all improvements must be designed and constructed with professional integrity and quality at the forefront . Additionally, designs will consider sustainability ( reuse of existing materials where practical ) and long-term total cost of ownership through life -cycle cost analysis . 1 . 3 APPLICABILITY The WCECC applies to all lot dividers, developers, landowners, and owners of facilities adjacent to or located in the County' s rights of way or easements — and to the employees, agents, or contractors of these entities — when they design , construct, and maintain facilities or conduct other activities subject to review and approval under the provisions of the Weld County Code . The WCECC also applies to the County and its employees, agents, and contractors . 1 . 4 REFERENCE DOCUMENTS The WCECC hereby adopts the latest versions of the following documents by reference . However, some of these references represent nationwide and statewide standards, respectively, which do not always satisfy County conditions . When standards differ, the instructions and guidance in this manual will govern . • American Association of State Highway and Transportation Officials ( AASHTO ) A Policy on Geometric Design of Highways and Streets • AASHTO Guide for Design of Pavement Structures • AASHTO Roadside Design Guide • AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing • AASHTO Standard Specifications for Highway Bridges WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A O F J 1 • AASHTO Load & Resistance Factor Design (LRFD) Bridge Design Specifications • AASHTO LRFD Bridge Construction Specifications • American Society for Testing and Materials (ASTM ) Annual Book of ASTM Standards • Colorado Department of Transportation ( CDOT) Access Control Plans • CDOT Bridge Design Manual • CDOT Construction Manual • CDOT Drainage Design Manual • CDOT Field Materials Manual • CDOT M& S Standard Plans • CDOT M-E Pavement Design Manual • CDOT Roadway Design Guide • CDOT State Highway Access Code • CDOT Standard Specifications for Road and Bridge Construction with Weld County Special Revisions (aka Weld County Department of Public Works Conformed Standard Special Revisions to CDOT's Standard Specifications for Road and Bridge Construction) • CDOT Survey Manual • Colorado Revised Statutes • Relevant Federal Emergency Management Agency ( FEMA ) documents • Federal Highway Administration ( FHWA) Manual on Uniform Traffic Control Devices (MUTCD) • FHWA Roundabouts : An Informational Guide (NCHRP Report 672) • FHWA Railroad/Highway Crossing Grade Handbook • FHWA Real Estate Acquisition Guide for Local Public Agencies ("The Uniform Act") • Institute of Transportation Engineers ( ITE ) Trip Generation Manual • Mile High Flood District ( MHFD ) Urban Storm Drainage Criteria Manual (USDCM) o MHFD is formerly Urban Drainage and Flood Control District ( UDFCD ) • Transportation Research Board (TRB ) Highway Capacity Manual • Weld County Code • Weld County Transportation Plan 1 . 5 INTERPRETATION This manual presents the basic criteria that must be met to ensure that infrastructure facilities are safe , efficient, economical, and appropriate for use in the County . Where minimum values are stated , greater values for safety, durability, or functional limits are encouraged whenever practical and consistent with federal, state, and local requirements . Situations might arise where the application of individual criteria from the WCECC will not ensure the protection of public health , safety, and welfare . Accordingly, Weld County may choose not to accept the infrastructure for taxpayer-funded maintenance ; may impose additional or more stringent criteria than those contained in the WCECC; or may require the modification of plans, specifications, or operations to protect public health, safety, and welfare . 1 . 6 ROAD ACCEPTANCE Acceptance of a road for maintenance by the County is at the discretion of the Board of County Commissioners ( BOCC ) and requires passage of a resolution . The Weld County Road Acceptance Policy requirements are available in Section 8-6- 150 of the Weld County Code . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF I 2 1 . 7 IMPROVEMENTS AGREEMENTS Subdivisions, Planned Unit Developments, Final Plats, Uses by Special Review ( USR ) and Access Permits may require the developer to sign an improvements agreement with the County and provide collateral to guarantee the improvements are completed as required for one or all the following reasons : • Off-site public improvements • Road Maintenance Agreement • Construction Maintenance Agreement • Access Improvements Agreement • On -site improvements for subdivisions/ PUDs More information can be found in Chapter 8, Article II , of the Weld County Code . An Improvements and Road Maintenance Agreement will detail the approved haul route ( s ) , outline when offsite improvements will be triggered , and include a maintenance agreement for the haul routes . Possible mitigations included in the road maintenance agreement may include, but are not limited to, dust control , specified haul routes, damage repairs, and future improvement triggers . An example agreement is available at : https : //www . weld .gov/files/sharedassets/public/v/ 1/departments/public-works/documents/ usr-spr- perm its- improvements-agreement-template . pdf Weld County uses the Equivalent Single Axle Load ( ESAL) methodology when calculating an Improvements Agreement proportional share . The ESAL methodology is a national standard for normalizing traffic counts to reflect the actual damage caused by large vehicles . The [SAL method data is as follows : * Add factors & equation . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE j 3 CHAPTER 2 ROAD CLASSIFICATIONS AND TYPICAL SECTIONS 2 . 1 ROAD CLASSIFICATION SYSTEM The County classifies roadways based on their function and whether they are urban or rural . These two classifications help designers determine the appropriate design characteristics for the road , including cross section and geometric standards . The functional classifications and urban/ rural classification consider anticipated traffic volume and access requirements on a road and determine the minimum right-of-way required . Together, these classifications help determine the minimum level of service ( LOS ) . They are a rational , cost-effective basis for the selection of geometric criteria within the range of values available to the designer. The BOCC adopts a Road Classification Map by ordinance and reviews it every two years . Changes made between the two-year reviews typically are based on development reviews and are made on a case- by- case basis via a public hearing process . The current Weld County Functional Classification Map can be found on the Public Works Department' s Transportation Planning web page . In addition , the Weld County Transportation Plan includes recommendations for when to modify road classifications . 2 . 1 . 1 Functional Classifications Function is determined based on the degree to which a roadway provides access and allows mobility . Roadways provide access when they allow travelers to easily reach most of the destinations within a given area . Roadways provide mobility when they allow travelers to easily go longer distances . The classification of Weld County roads is comprised of a hierarchy of roadways whose functional classifications are defined by their usage . The relative degree to which a road serves these functions defines its functional classification . Roads in Weld County are classified as Arterial, Collector, Local , or Private Roads . The functional classifications of roadways used by Weld County are described below . 2 . 1 . 1 . 1 Arterials A county highway refers to a highway defined in House Bill 16- 1155 . In Weld County a county highway is a four- lane controlled -access arterial road intersecting with an interstate highway, United States numbered highway, or State Highway . Roads that were annexed before the County' s designation of the road as a county highway also may be included by intergovernmental agreement ( IGA) with the municipality . Weld County has designated Weld County Road 49 ( WCR 49 ) between Interstate 76 ( 1 -76 ) and U . S . Highway 34 ( US 34 ) Weld County Parkway, and Weld County Road 47 ( WCR 47 ) from the Parkway to State Highway 392 ( SH 392 ) as county highways . See the Weld County Functional Classification Map, available on the County' s Transportation Planning webpage . The county highway designation means Weld County will govern all substantive aspects of the road , including access, maintenance, traffic control , speed limits, and overweight limits, even if municipalities later annex the road . Arterials provide good mobility, carrying significant traffic volumes at high speeds for long distances . They are seldom spaced at closer than one- mile intervals and serve to connect larger communities . The primary difference between interstate highways and arterials is access . Interstate highways have fully controlled accesses with no at-grade intersections, while arterials include limited at-grade intersections . WELD COUNTY ENGINEERING 8z. CONSTRUCTION CRITERIA PAGE 1 4 2 . 1 . 1 . 2 Collectors Collectors link local roads with the arterial road system and connect smaller communities . Both mobility and access are of equal importance on these roadways . Travel speeds and volumes are moderate, and distances traveled are short to medium . Traffic on collector roads typically has an origin or destination within the nearby area . Weld County has both paved and unpaved collector roads . 2 . 1 . 1 . 3 Local Roads Local roads primarily provide access to adjacent land in rural and urban areas . Local roads are closely spaced and carry relatively lower traffic volumes for short distances . They generally are internal to — or serve an access function for— a residence, farm , single neighborhood , or development . Generally, they should lead traffic to a collector road . 2 . 1 . 1 .4 Privately Maintained Roads Weld County may review privately maintained roads that are planned to be used by the public, such as a road within the boundaries of a residential subdivision , but the roads will be maintained by a homeowner' s association ( HOA) or other private entity . 2 . 1 . 2 Primary vs Secondary Classifications In addition to classifying roads by function , Weld County classifies roads as Primary or Secondary per ( C . R . S . ) § 43 -2 - 101 . Primary roads usually serve more developed areas and diverse uses ( e . g . , bicyclists, pedestrians, on - street parking, etc . ) . Primary roads usually are paved , with curbs, gutters, and sidewalks . Often , they connect to an existing stormwater drainage system rather than making use of roadside ditches ( which are found commonly beside rural roads ) . Secondary roads primarily serve less developed areas and lower volumes of vehicular traffic . Most of the roads in Weld County are classified as secondary . However, roads that are in municipal Urban Growth Boundaries may be classified as urban/primary . 2 . 2 RIGHT - OF-WAY WIDTHS The minimum right-of-way widths are as follows, unless otherwise approved by the BOCC : Arterial 140 feet Collector 80 feet Local 60 feet 2 . 3 RIGHT - OF-WAY USE PERMIT Permits are required when working within the County road right-of-way . More information can be found in Section 11 . 2 of this document . See also Weld County Code, Chapter 8, Article XIII , Sec . 8- 13 - 10, et seq . It is not the intent to allow new private irrigation systems to be located within County road right-of-way . 2 .4 RIGHT - OF-WAY DETERMINATION On October 12 , 1889, the BOCC declared all section and township lines on the public domain of the United States in Weld County to be public highways with the intent of constructing roadways on these WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE ( 5 lines . With this order and for this purpose , the BOCC also established 30 feet of road right-of-way on each side of the section or township line ( a total of 60 feet ) . Sections not included in the public domain are railroad sections, school sections ( usually 16 and 36 ), and sections patented prior to October 12 , 1889 . Not all County roads are a result of the 1889 Resolution . Many Weld County rights of way have been conveyed by landowners through road petitions and dedications, as well as Weld County acquisitions working with landowners . Due to topography, cost, and other factors, not every county road is situated within the 60-foot road right-of-way and/or centered on the section line . In some places, additional right-of-way has been acquired or reserved . The right-of-way section of the Public Works web page discusses this in more detail . The County recommends that designers review this information and also do their own research into right of way in the areas of their projects . The Weld County right-of-way road files are located in the office of the Clerk to the Board at 1150 O Street in Greeley, Colorado . Please call ( 970 ) 400-4225 to set up a time to come in . 2 . 5 RIGHT - OF-WAY ACQUISITIONS Acquisition of road right-of-way will substantially follow the Real Estate Acquisition Guide for Local Public Agencies published by the FHWA, the Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970, 42 United States Code ( U . S . C . ) Ch . 61 (the " Uniform Act" ) , and Title 38 of the Colorado Revised Statutes ( CRS ) . 2 . 6 TYPICAL CROSS - SECTIONS While it is important to try to preserve the ultimate road right-of-way, funding availability does not always allow for construction of the ultimate section and , in such cases, an interim section should be constructed until funding becomes available . The Public Works Department determines whether a road is designed to the interim or ultimate ( or combinations thereof) road cross section . This determination is based on funding, existing and projected traffic volumes, connectivity, continuity, mobility, and capacity . If only a portion of the ultimate cross section is being constructed , the interim design will need to allow for eventual widening of the road to the ultimate cross section . The interim design should ensure that the first phase of the roadway will not need to be removed to complete the full cross section . Storm drainage designs and floodplain analysis will be considered and be constructed to accommodate the ultimate section , unless written approval is obtained from the Public Works Department . All designs should consider how the roadway is used , long-term traffic predictions, location and density of nearby development, and topographical characteristics . A roadway constructed to the ultimate cross section still may require more right-of-way and roadway width in the future for additional lanes, pedestrian or bicycle facilities, landscaping, utilities, or construction requirements, such as cut or fill slopes . Designers should try to anticipate such needs . Other chapters within this manual will discuss design considerations in more detail . Table 2 - 1 ( Rural Conditions) and Table 2 - 2 ( Urban Conditions ) summarize some of the features incorporated into the typical cross section drawings for the different road classifications . Figure 2 - 1 through Figure 2 -8 present examples of typical cross section drawings for interim and ultimate roadway types found in the County . Note that the tables and typical sections in this manual usually reflect minimum requirements . The Public Works Department may impose additional requirements on a case- by-case basis . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA I 6 Table 2-1 Typical Cross Sections Summary ( Rural ) Number of Roadway Right-of-Way Road Travel Lanes Travel Lane Shoulder Width Median Width Sidewalk Classification Width ( min . ) Surface ( min . ) Width ( min . ) ( min . )/Type ( min . )/Type Drainage Type Width ( min . ) RURAL ROADS ( INTERIM ) Arterial 140 ft Paved 2 12 ft 6 ft Paved N/A Roadside Ditch N/A 2 ft Gravel Collector 80 ft Paved 2 12 ft 4 ft Paved N/A Roadside Ditch N/A 2 ft Gravel Collector 80 ft Gravel 2 12 ft 2 ft Gravel N/A Roadside Ditch N/A ( Unpaved ) Local ( Unpaved ) 60 ft Gravel 2 12 ft 2 ft Gravel N/A Roadside Ditch N/A RURAL ROADS ( ULTIMATE ) County 140 ft Paved 4 12 ft 8 ft Paved 16 ft Roadside Ditch N/A Highway 2 ft Gravel Paved Arterial 140 ft Paved 4 12 ft 8 ft Paved 0 ft to 28 ft Roadside/ Median N/A 2 ft Gravel Paved or Ditch or Storm Unpaved Sewer Separation Collector 80 ft Paved 2 12 ft 6 ft Paved 0 ft to 16 ft Roadside Ditch N/A 2 ft Gravel Paved Local 60 ft Paved 2 12 ft 1 ft Paved N/A Roadside Ditch N/A 1 ft Gravel Non -maintained 30 ft Unpaved 2 10 ft 2 — 5 ft Gravel N/A Roadside/Utility Ditch N/A Local - RAP Culverts need to be Residential located outside of ROW on landowner property Non - maintained 30 ft Unpaved 2 13 ft 2-2 ft Gravel N/A Ditch swale N/A Local — Gravel Culverts need to be Residential located outside of ROW on landowner property WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE I 7 Table 2-2 Typical Cross Sections Summary ( Urban ) Number of Roadway Right-of-Way Road Travel Lanes Travel Lane Shoulder Width Median Width Sidewalk Classification Width ( min . ) Surface ( min .) Width ( min . ) ( min . )/Type ( min . )/Type Drainage Type Width ( min . ) URBAN ROADS ( INTERIM ) Arterial 140 ft Paved 2 12 ft 6 ft Paved N/A Roadside Ditch or N/A 2 ft Gravel Storm Sewer Collector 80 ft Paved 2 12 ft 5 ft Paved N/A Roadside Ditch N/A 1 ft Gravel Local 60 ft Paved 2 12 ft 1 ft Paved N/A Roadside Ditch N/A 1 ft Gravel URBAN ROADS ( ULTIMATE ) Arterial 140 ft Paved 4 12 ft 16 ft Paved * 16 ft to 28 ft Paved Curb & Gutter and 10 ft or Raised Median Storm Sewer Collector 80 ft Paved 2 12 ft 8 ft Paved * 0 ft to 16 ft Paved Curb & Gutter and 5 ft Storm Sewer Local 60 ft Paved 2 12 ft 8 ft Paved * N/A Curb & Gutter and 5 ft Storm Sewer * includes gutter pan width WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE I 8 Figure 2-1 Rural Local and Collector Roads ( Unpaved ) (Interim) I R.Q.W. (See Note 5) 4 i kes 28' - - }+ 16' +r_ 2' 12t 12' 2'Wm t nit16' t /- wit Os Buffer Shoulder-, ~ Travel Lane i Travel Lane Shoulder Buffer Varies .. I I•I 3°i 4% 1 3°f°=4�ro .N.} mot# :sTiT- _ tea► r '" �T� st• .� b.� a► li: i[ i`_�IrC � i- 1 -.1111"' �: . ./ I * ABC Compacted Subgrade INTERIM TYPICAL CROSS SECTION Typical Gravel Road Notes: I . * The allowable class and thickness of Aggregate Base Course (ABC) shall be determined by the guidelines described in the Pavement Design Chapter. 2. The foreslopes and backslopes shall be no steeper than 4: 1 with a preference of 6: 1 or flatter where it can be accommodated. 3. All sideslopes shall be seeded and mulched. 4. Additional ROW may be required by Public Works to meet site specific requirements. 5. Width of ROW shall be determined by NOT TO SCALE classification of road. 6. Signing per approved plan. Computer File Information WELD COUNTY Creation Date: 02i10, 10 laitn(': KH PUBLIC WORKS DEPARTMENT INTERIM RURAL LOCAL last Modification Date: O4:UW�l6 Initials: ddd , ,,. AND COLLECTOR ROADS Full Path: T:TBSC admin riProposals\Wcldc I l t t H S*rcct Pc, Office Box 75$ 1 r; . % Greeley. Colorado 8063„-1758 RatStN1: ' Drawing File Name: 1 -_,43" r Phone: (970) 3(M-696 Iksiitncr: Weld County Fax: (970) 3(t-6497 Revise;: FIGURE NO. 1 hitcrotutk+i Vet. XXI Sea*: N.T.S. Unil.: English Dcui:kr K_ llinnenkamp WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 19 Figure 2-2 Rural Local ( Ultimate) ci 60' .O.W l 2W .+ t 16' 2' 24' .•. 2' 16' 'Once .0 Buffer Shoulder -� Shoulder Buffer r Varies ` .. 12' ' 12' Imp* Travel Lane .•, Travel Lane r r * HMA t 2% 2% riga vg- • - sea 41 1•1 a .11 l l l� il: l-lidll U lft.T . 11_11•-'II ganne �� I1cIk ABC Compacted Subgradc • (Class 5) * LIMA -- TYPICAL * ABC (Class 6 ) CROSS SECTION Notes: 1 . * The allowable class and thickness of Hot Mix Asphalt (HMA) and Aggregate Base Course (ABC) shall be determined by the guidelines described in the Pavement Design Chapter. 2. The foreslopes and backsiopes shall be no steeper than 4: 1 with a preference of 6: 1 or flatter where it can be accommodated. 3. All sideslopes shall be seeded and mulched. 4. Additional ROW may be required by Public NOT TO SCALE Works to meet site specific requirements 5_ Signing and striping per approved plan. Computer File Information WELD COUNTY ("ratitena: 1►21u. 1 "labK" PUBLIC WORKS DEPARTMENT Last mutton dale. o f to4 ► _ Kit 1.n. _;, RURAL LOCAL Full Pak Pam * Adman !'cu � al, « rhi�fr 1111 11 Simi Poo Otl'ae Bo% '-• nie Gra Icy Colorado I8OQJ2.OT t, :lc Dra Fik Vnte Pisa 1v70) 30 -6496 . .I T11 cid ( 'own!, Fat eiT i3w. T - - FIGURE NO. 2 11►c:oit z on 1 ;r NM h.Y.S l ruti E'ngii•h .ktad K 11inncnkamp WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 110 Figure 2-3 Rural Collector ( Paved ) 80' R.O.W. 36' .� r • 22' 24' 6' 22' «. 6' PSI ' - % Pal ih- Buffer Shoulder / E Buffer Shoulder Varies `t' ... 12' ,�. 12' 4' .. Travel Lane , Travel Lane 1 * HMA p 2% , 2% — m\, ,,,, , -. , / w II , SI6EV,Minfs'7,14' 1 � \/ l ABC (Class 5) Compacted Subgrade * HMA — INTERIM TYPICAL ' _ * ABC (Class 6) -- CROSS SECTION Shoulder/.2 Eli Multi-Use ' .. 8Q' R.O. W.W 40' 4 , S 20' 8' 4' 8' 20' Buffer houlder/ Shoulder Buffer Multi-Use iMulti-Use ,.. Varies 6' 12'..4� __ ► ' 6' _ 12 ,...� }. Travel Lane ' Travel el Lane I * HMA 10 , 2% C ♦'� _-_��_r!!�� a ��,mil I_j�..� �� - �.-_��„f` �vt.Pi s. il- - N:`e ! .NSA• — — n ` 4 il-i iitt v (Cl ) -- Compacted Subgrade - * HMA — - * ABC (Class 6) — ULTIMATE TYPICAL CROSS SECTION Notes: 1 . * The allowable class and thickness of Hot Mix Asphalt (HMA) and Aggregate Base Course (ABC) shall be determined by the guidelines described in the Pavement Design Chapter. 2. The foreslopes and backslopes shall be no steeper than 4: 1 with a preference of 6: 1 or flatter where it can be accommodated. 3. All sideslopes shall be seeded and mulched. 4. Additional ROW may be required by Public Works to meet site specific requirements. NOT TO SCALE 5 . Signing and striping per approved plan. Computer File Information WELD COUNTY Creation Date: 02/1010 hut;als: Kit PUBLIC WORKS DEPARTMENT RURAL. COLLECTOR Last Modification Dec: 01/04.: 12 Initials: K!l 11 ) 1 II Street Post oilicr Box 75a Approved: Full Path: T:\PBSOAdmin\Prupusals'.Wcldc ,s I. Omelet', Colorado $0632.075$ ReVS: mewing File Name: yj -P. r ? Phone: (970) 304-6496 - `ks►ttner. Weld County It Fax (970) 304-6497 Rr'tscd: FIGURE NO. , Micn>statS Vet. XM Scale-. N.T.S. Units: English Dctaikt K Hinnenkamp WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1 11 Figure 2-4 Rural Arterial I 140' ¶t.O.W. . Ill M 4n' ... 8' ... 24' at. 8' 50' Buffer I Buffer Varies Should 6r 6' 12' L2' 6' es houlder ,. "ravel Lanc I rave Lane f 2° <7 4 f. 9<je r a. se amminnes elaNta. ABC Compacted Subgrade \ (Class 5) — • HMA — — • ABC (Class 6) INTERIM TYPICAL CROSS SECTION tt I s. 140' ¶.O.W. 84' - 96' .. 22' - 28' .., 10' 24' 0' - Z8' .•. 24' 10' 22' - 28' ., Buffer Shoulder/ ' aved or Unpavec Shoulder/a. Buffer Multi-Use Sepatation ' Multi-Use Varies Vane 8' 12' 12' 12, 8 ravel Lane Travel Lane 1 1 • 1 1 ietravel Lane"Travel Lane 2% ill I • HMA 2°/ �.r �� tiltararanitatir>swet i t =t t d i , — E r�+Ca . �� Q. 1 5 l'i .elan tamtil m'll i� _ % tit is . 1 .1.--_v,_lilie' .+at=. iii • PIMA $ • ABC (Class 6) �- una Cirli Suh4.1 r:,cls.• Qt -- Pa — ABC '' HMA — ABC( (Class 5 ) Class 5) ULTIMATE TYPICAL CROSS SECTION Notes; 1 . * The allowable class and thickness of Hot Mix Asphalt (HMA) and Aggregate Base Course (ABC) shall be determined by the guidelines described in the Pavement Design Chapter. 2. The foreslopes and backslopes shall be no steeper than 4: 1 with a preference of 6: 1 or flatter where it can be accommodated. 3 . All sideslopes shall be seeded and mulched. 4. Additional ROW may be required by Public NOT TO SCALE Works to meet site specific requirements. 5. Signing and striping per approved plan. Computer File Information WELD COUNTY Crcahbctkte 02'III' I0 Slit. KH PUBLIC WORKS DEPARTMENT RURAL ARTERIAL t ast M,*hti;atan l kr 01.1)4 1 -2 In,tul. 10i ‘ � F �I Pa PBSC',�dmrn Pro ial ' V1'rlJc t t 1 , N Street Post Mice Sot 75$ , • • 1 Crocky. Caiarado IMP-07% Rota t Plus (970) 3G144 of Diann Fit -r 1kup+cR, Wr1J County 41 r Fat. (970) 14144497Ra : FIGURE NO. 4 %InroacnhK, 1 :s Vel Sal.: N I S inns Fn tli%h thither K Wtnncnkamp WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 112 Figure 2-5 County Highway i 140' R.O.W. se 28' _ 10' ..«. 24' _ 16' Imo24' sow10' 28'«se Buffer Shoulder/ Left Turn Lane Shoulder/ Buffer Multi-Use . 12' ,,,y 12' t 12' w 12' Multi-Use 8' Travel Lane Travel Lane 'crave . Lane Travel Lane 8, ` _ - Varies ..-- .• * PCC t rl - mow- �.�.�� !�� !.- i..f�' !-� �M� �:�.� 1 .. bales+� "c J• :rim..1.S0 3r7a':Ga Li. 1.�1.._ L._ _. L_..�..,.. L.IZ a tiv� -_"' .1..a, :yam .c cc S �. , �.d kO�„1NI1-1i-ll ff: A II9..F11=� It lig iau rt�tzt�rtt.t�ii�.n.-11rigOgairtl=lien il'—III"i1=_ .I II 'INFL, HI-11;a11=11aa. 4J4 >7 * ABC (Class 6) tea\ Compacted Subgrade COUNTY HIGHWAY TYPICAL CROSS SECTION Notes: 1 . * The allowable class and thickness of Portland Cement Concrete (PCC) and Aggregate Base Course (ABC) shall be determined by the guidelines described in the Pavement Design Chapter. 2. The foreslopes and backslopes shall be no steeper than 4: 1 with a preference of 6: 1 or flatter where it can be accommodated. 3 . All sideslopes shall be seeded and mulched. 4. Additional ROW may be required by Public Works to meet site specific requirements. NOT TO SCALE S. Signing and striping per approved plan. Computer File Information WELD COUNTY Creation late: 02.'1 ai l0 InitiaLk: KH PUBLIC WORKS DEPARTMENT COUNTY HIGHWAY Lase Modification Datc: 01/04/12 Initials: K!t tilt ti StrcevPost Office Box 758 ed' Full Path: T:`c,PBSC.Admin\Proposals1Veldc Ai ('rrrlcy. Ci,k,rsdo 8tlt+32M75$ Rnisod: Drinking Ely Name: ' . ,,t Phone: 4970) 3t1`td,496 Designer. iNcld County Fax: 4970) 304-6147 Ktviscd: FIGURE NO. 5 MicsmUtinn Vet X141 Scale: N.T.S. Units: English Ruler K. Hinnenkamp WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 113 Figure 2-6 Urban Local 41 .. w •O.W. .r r 2W ,r ..• I 16' 2' 24' — 2'' Shoulder 16' Bunerme ON Buffer Varies "Lie 12' I 12' t' • - -.. Travel Lane I Travel Lane sm. um I * HMA 2% I 2% �•� si �t•1 i �? fl* �f�1i� SWAt.� '7I web= •t • / 41= r■ -- ..- —• .— ..f�..Tri !'rr•II�r♦u'h 1s� sseav ��.. ..^^ -u �r. "4 2 •\<<fghlriirI I;:Lj.-II II-_ I1._ iI- -_ ii-Ii=11=11�ii=11=HI�l1s r N ABC (('lass 5) Compacted Suhgradc * HMA INTERIM TYPICAL • ABC (Class 6) -- CROSS SECTION ci I ,. 60' R.K . W. es I 0' 40' 10' me 600 Sidewalk/ Sal • `�' Sidewalk, Curb/ I Curb/ Buffer .• s. 8' .�•. 12' t i -c 12' sae as rt S_� Buffer Travel Lane Travel Lane Shoulder, Multi-Use I Multi-Use -- 4�tij ' HMA ` 2° 0 �ra��— _, a-att. I Sao a. Os*. MINI CM � . . a a a _•—S." . 7 awe erit tWa s, sitTeire ieiS i�..",treawI ra&t' reua�.ve�.•:n►, as as ,..—SL ILr-..r-err• ,—t>trirt--rt--..—..--..--..—.. - I1=11=11=11=1;-=[1=1i=lI III =ii=ii-II -1i=11.u "--11 1ft Compacted Subgrade ' ABC (Class 6) Notes: ULTIMATE TYPICAL I . • The allowable class and thickness of Hot CROSS SECTION Mix Asphalt (AMA) and Aggregate Base Course (ABC) shall be determined by the 5' Minimum Sidewalks as Required by Public Works guidelines described in the Pavement Design Chapter. The foreslopcs and backslopes shall be no steeper than 4: 1 with a preference of 6: 1 or timer where it can be accommodated. 3• All sideslopes shall be seeded and mulched. 4- Additional ROW may be required by Public NOT TO SCALE Works to meet site specific requirements. 5• Signing and striping per approved plan. Computer File Information WELD COUNTY r NW. 02' la, lo Sufi ttt , PUBLIC WORKS DEPARTMENT IaI M$d cnm t 01 0412 tnawh KU URBAN LOCAL I 111111 Strom Post olficc t3au 7514kaxu�r`i. F.dI Psi T: PF3Sr Admin Pre xkalc V1 cldr ic , i ...2. ' t Quin. Colorado M*rf M7SM Ding Fit \amc /, • .r ► Ptks; t97o sai•6.•o nova: Weld County A . Fat (t7o) X04.6491 Robed FIGURE NO. 6 11n:tehtttpat 1 c XM S;.►:: N T S 1 nds. Fntt►+l► ()cilia k tlinncnkamp WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1 14 Figure 2-7 Urban Collector is 80' R.O.W. .., I 1 36' _ •• I 22' • '• 4• 2 . Buffer ++ •S . \L. Buffer Shoulder ' Shoulder S' •-• 12' s 12' 5' es Varies Travel Lane , Travel Lane . , I • HMA 2% I 2% _� _ 4 s ":41.! e we ■► w fib • • WW • W t/�!•l t•� tt►�.tre We we a ,/'a C . .. .. ... i t -- air'ate II?fra..1tr11"st.^nl /1 .M� Ns. IA % c 0 -II-II-II- rii:r711--I1;411-11-II=II=II "uh' II- - - •— -- �lt. Noe ABC (Class 5) Compacted Subgrade * HMA — * ABC (Class 6) INTERIM TYPICAL air CROSS SECTION ci r tea iio.w. ., I I I ?2' 4W 2? •. 11 Stdcwalk ~ SidewaLc/ Curti. le Curb' I Buffer els. r . t . r►_a 121 J a 12' �.r S' • �. S'�r Buffer travel [.law 1 Travel La see Muhi-Use t Multi-Use �� .'�- _ a • HMA I amemp• lama n..“..!.°\ :41P" 1."0.r;abea ts�V1T '-� :sit-Z ♦��sits z"1 .,: 71�'1_ilIIkr`_',�►-a'IS s �Ns• ' 4' rf 1111"-11'- lf -- 11-11- 1, 2-11 - nlI-=11 .=11x11 tlsll.rli liiiil n• ea ( I I Compacted Subgradc ABC (Class 61 ULTIMATE TYPICAL CROSS SECTION 5' Minimum Sidewalks as Required by Public Works Notes; 1 . * The allowable class and thickness of Hot Mix Asphalt (HMA ) and Aggregate Base Course (ABC) shall be determined by the guidelines described in the Pavement Design Chapter. 2. The foreslopes and backslopes shall be no steeper than 4: 1 with a preference of 6: I or flatter where it can be accommodated. 3. All sideslopes shall be seeded and mulched. 4. Additional ROW may be required by Public NOT TO SCALE Works to meet site specific requirements. 5. Signing and striping per approved plan. Computer File Information WELD COUNTY C'reat,x0ete 02:IalO laity KH PUBLIC WORKS DEPARTMENT ( .n1 1�t1�Jr1�;�t�unnasc 01 l►.t l _ croak KU URBAN COLLECTOR 1prin`ti1. I t t I H Suen Post Office B Bon 75s Eill Pail r PBS('Admrn'Pruptnals Weldc Is. : ' t* , Omsk,. Cando 1€061..O.%* Rr�l,a! a 1k _ , sut.a r ►: 1�'�•W c tx,nty FIGURE NO. 7 Sllcr► 'utrcu 1 e X111S:sl. N r S huts r-ngInti Fart t'?It) �� Ke"�� Under K inncnkanqi k WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 115 Figure 2-8 Urban Arterial if - 140' R .O. W. l 40' 5 2' S' . 24' 8' 5?' r r Buffer i Ii Buffer Varies Shoulder 6' 12' ____ 12' 6' Shoulder ravel Lane- Travel Lane * HMA . 1V 1 2V. fH -I1 =II=I1==1t=.11 iI=Ih �-I1==l111= 11.=11= 11=II^ll:.11.=1 .. cost �' js" ABC Compacted Subgrade (Class 5) * HMA — — * ABC (Class 6) INTERIM TYPICAL CROSS SECTION c, I 140' R.O. V. i I 16' - 22' 16' 24' 16' - 28' 24' 16' 16' - 22' L. ,,,li Sidewalk/ Shoulder/ Raised Median Shoulder! Sidewalk/ Curb/ Multi-Use 12' • 12' a 12' 12' Multi-Use Curb/ -41 Buffer Travel Lane Travel Lane ' Travel Lane Travel Lane Buffer — 10 * HM r 10' �..�.kagn .-srierr•itedintiC�t.vR/i_ l WSZ Y �argairr _: ear..� re rig s1 .-'a".r:S�..�F.I:'it Pe�otaa -.', a.—ia—. Ill�lf—If�ll�il 11 rl-•IJ-JJ-JJ•-It III-"'II—II III II—^IJr'II�'tJ�LI—II —ILtIL—IL—I��ll •!. s�—�� 11:4 7f=11Q=n i imiwi 1' i=1ta24.14451fffana f=ll:-ar=n=n--n rU-n-lt=JJt1(Ltif=lf�lr'tf.»If 11-* -t(=if=fy p= t jrei1�=1i«-iulii= I �L�LL�p .rl5�tlu ...� ..- n," �..__t.�-/.�.IIr.1L_fl_, .. J _ 1 ' * ABC (Class6) ' ULTIMATE TYPICAL Compacted Subgrade CROSS SECTION 10' Minimum Sidewalks as Required by Public Works Notes: i . * The allowable class and thickness of Hot Mix Asphalt (HMA) and Aggregate Base Course (ABC) shall be determined by the guidelines described in the Pavement Design Chapter. 2. The foreslopes and backslopes shall be no steeper than 4: 1 with a preference of 6: 1 or flatter where it can be accommodated. 3. All sideslopes shall be seeded and mulched . 4. Additional ROW may be required by Public NOT TO SCALEWorks to meet site specific requirements. 5. Signing and striping per approved plan. Computer File Information WELD COUNTY Creation Date: 02/10/10 Initials: KN PUBLIC WORKS DEPARTMENT URBAN ARTERIAL Last Modification Date: 0I;Ml12 Initials: Kl I thofFull Pa: Tf.PBSC•Admin\Proposals\Welde 11 1111 Street/Post Office Box 158 � `►`al , Grectry. Colorado 80632-0'58 Rev cd: Drawing Fik Name: _ , . Phone: (970) 304. 4% Designer: Weld County L.' - Fat (970) 304-6497 ,z0;., ;FiGURE NO.8 Mica Cation Va. XM Scale: N.T.S. Units: English --- - a _ Dctaikr- K. Hinnenkamp WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 116 CHAPTER 3 SURVEYING 3 . 1 SURVEY DATA - REQUIRE A SURVEY CONTROL SHEET The required horizontal datum for surveying in Weld County is North American Datum of 1983 , NAD-83 . The required vertical datum is North American Vertical Datum of 1988, NAVD-88 . 3 . 2 STATE PLANE It is required that survey control be tied into a National Geodetic Survey ( NGS ) monument for state plane conversion . Please refer to the NGS website for monument information and location . 3 . 3 MONUMENT BOXES Monument boxes are available at no charge for surveyors with valid permits who are upgrading aliquot corners on paved Weld County Roads or placing monumentation for aliquot corners on new paved Weld County Roads . Please contact Public Works in advance at ( 970) 400-3750 . 3 .4 ROAD SAFETY Appropriate traffic control devices and safety equipment are required when surveying within the County right-of-way . For the safety of the traveling public, monument box covers must be replaced , or the holes created must be backfilled . To minimize damage to the asphalt, concrete collars will be required around newly installed monument boxes . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 117 CHAPTER 4 ROADWAY DESIGN CRITERIA 4. 1 GENERAL 4. 1 . 1 Policy on the Use of Referenced Publications This chapter summarizes and/or supplements standards that have been prepared by AASHTO . The County expects and recommends that transportation designers reference the most recent edition of AASHTO' s A Policy on Geometric Design of Highways and Streets as a primary guide when designing roadways in the County . Designers also are expected to reference CDOT design manuals . However, AASHTO and CDOT policies represent nationwide and statewide standards, respectively, which do not always satisfy County conditions . When standards differ, the instructions and guidance in this manual will govern . For the design of auxiliary turn lanes, please see Chapter 8 of this document . All traffic control devices and road striping will be in accordance with the latest version of the MUTCD or as shown in the latest version of CDOT' s M& S Standard Plans . 4. 1 .2 Typical Plan Set Guidelines Typical plan sets should include enough detail and documentation to allow successful construction of the proposed transportation improvements . Plan sets found to be incomplete, or of insufficient quality to be easily readable by the reviewer( s ), will be rejected by the Public Works Department . Plan sets will be produced on 11 - inch x 17- inch paper and may be submitted electronically . All plan sets will be prepared by or under the direct supervision of a Professional Engineer licensed in the state of Colorado . Each sheet will be stamped and signed by the Professional Engineer of record . The following elements also must be included : • Cover Sheet . Must include a vicinity map with scale and north arrow, an index of sheets, design data , the phone number and address of the company and/or engineer responsible for the drawings, a utility contact list with phone numbers and email addresses, the Utility Notification Center of Colorado ( UNCC ) phone number ( 811 ) , the project title, and the date printed . • M &S Standards Sheet . Must show which M &S standards from the most recent CDOT M& S Standard Plans are applicable to the project . • Typical Section Sheet(s) . Must include functional classification of the roadway, rural or urban classification of the roadway, right-of-way width , lane and shoulder widths, road centerline ( crown ) location , typical cross-slope , and pavement structural section elements and thicknesses . • General Notes . Must include all notes that are applicable to the construction of the project . May also include notes on pavement design , Best Management Practice ( BMP ) design , etc . • Summary of Approximate Quantities and Earthwork Quantities Sheet(s ) . Must include tables showing the bid tabulation quantities and breakdowns of all quantities by location . • Survey Control Sheet(s) . Must include the basis of elevation control, basis of bearings, and project coordinates datum . • Right-of-Way Plan Sheet(s) . Must be included when temporary or permanent easements are needed or right-of-way will be acquired . Must include scale and north arrow, existing right-of- way lines, parcel lines and data , ownership information, proposed easement or right-of-way lines, and existing and proposed improvements . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 118 • Utility Plans Sheet(s).Provide existing(SUE)and proposed utility relocations.Both plan sets must include scale and north arrow,utility ownerships,utility locations,utility conflicts.The SUE sheets shall provide the appropriate level of mapping meeting Colorado state legislative subsurface utility engineering(SUE)requirements.County requires Quality Level B or better for all utility impacts.The utility plan should also show the location of where utilities are proposed to relocate. • Demolition and Removal Sheet(s).Must show existing conditions and include all items that are to be removed or demolished by the contractor as part of the project. • Plan and Profile Sheet(s).Must include horizontal and vertical scales and north arrow,location of right-of-way,location of easements,location of property lines,location of utilities,centerline stationing,horizontal and vertical curve information,existing and finished road grades,and design elevations.Separate plan and profiles sheets will be included for each access point, irrigation structures,and other structures as applicable. • Intersection Detail Sheet(s).Must include roadway centerline with stationing,north arrow, horizontal scale(1 inch=20 feet preferred),proposed and existing contours(1 foot minimum), grade flow arrows,location of right-of-way,curb type label(if applicable),and critical spot elevations. • Grading and Erosion Control Sheet(s).Must include existing and final elevation contours at a minimum one-foot contour interval,spot elevations at critical drainage points to facilitate review and construction,slope/flow arrows and labels,limits of construction disturbance,and location of permanent erosion control features.If the project requires a Stormwater Permit per the National Pollutant Discharge Elimination System(NPDES),a detailed stormwater management plan(SWMP)and landscaping/vegetation plan will be required.(Additional information can be found in Chapter 6 of this document.) • Drainage Sheet(s).Must include location and type of all drainage features(e.g.,pipes,ditches, inlets,manholes),details for pond spillways and outlet structures,plan and profile views of all pipes and culverts(unless new pipes or culverts are replacing existing ones of the same size and at the same location),location of all existing utilities,utility potholing,identification of utilities that conflict with new drainage features,and construction details.Labeling is required for any pond water surface elevations(WSEL),volumes,water quality capture volumes(WQCV),and elevations.Drainage sheets must correspond to the accepted drainage report. • Signage and Striping Plan Sheet(s).Must include driving lane and shoulder widths;stationing locations for striping beginnings,endings,and changes;color and size of striping;striping material type;stationing location for signs;type and size of signs;and quantities tabulation tables. • Landscaping Plan Sheet(s).Must include all areas that are to be seeded and/or landscaped.If trees are to be replaced,they must be shown on this plan subset. • Phasing Plan Sheet(s).If the project is to be phased,the phasing plans must be included. • Construction Traffic Control Plan Sheet(s).Must include plan view of all existing roads within the limits of the detour or within one mile of the project,whichever is larger;type and size of signs or other traffic control features;locations for all traffic control features;and quantities tabulation table.These sheets also must show any anticipated detour routes for road closures during construction. WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE 119 • Cross Section Sheet(s).Cross sections on 50-foot interval must include depiction of existing and final ground elevations,location of existing and proposed right-of-way and easement lines, utilities,station labeling,and roadway centerline location. • Stormwater Management Plan.Must determine whether site is located in a Municipal Separate Storm Sewer System(MS4)area and must be included for temporary and permanent control measures.See Chapter 6 of this document for more information. These guidelines are not intended to replace specific guidelines related to preparation and submission of plat maps and property description maps prepared by a licensed professional surveyor.These guidelines also are not inclusive of all the specific items that may be required by the Weld County Public Works,Planning or Building Departments.There may be additional requirements for more complex projects,such as bridge replacement and County Highway projects. Table 4-1 below summarizes the roadway design criteria that can be found in this document for each roadway classification.For additional details refer to the sections below that discuss each topic. WELD COUNTY ENGINEERING&CONSTRUCTION CRITERIA PAGE 120 Table 4-1 Roadway Design Criteria Design Element Arterial Collector Local Design Speed Within Subdivisions 60 mph 50 mph 40 mph Outside Subdivisions See Note 1 Posted Speed Within Subdivisions 50 mph 40 mph 30 mph Outside Subdivisions See Note 1 Design Vehicle WB-67 WB-67 WB-67 Maximum Superelevation Rural 6% 6% 6% Urban 4% 4% 4% Minimum Tangent Between Curves in Addition to Superelevation Transition Length Required 100 ft 100 ft 50 ft Minimum Intersection Tangent ( Measured from Pavement Edge) ( See Note 2 ) 200 ft 150 ft 100 ft Minimum Centerline Radius See Note 3 Minimum K Value for Vertical Curves See Note 4 Minimum Stopping Sight Distance See Note 4 Minimum Centerline Grade on Road with Curb and Gutter 0 .40% 0 . 40% 0 .40% Maximum Centerline Grade 5 % 6% 8% Maximum Vertical Grade Change Not Requiring a Vertical Curve ≤0 . 2 % ≤0 . 2 % ≤0 . 2 % Minimum length for Vertical Curves Preferred : 300 ft 300 ft 300 ft Allowed ( 3 x Design Speed ) : 180 ft 150 ft 120 ft Notes: 1 . See Section 4. 1 . 3 to determine an appropriate design speed and posted speed limit. Enforceable speed limit for roads without a posted speed limit is 55 mph. 2. See Figure 4-2. 3. See AASHTO 's A Policy on Geometric Design of Highways and Streets superelevation tables for minimum radii based on design speed and maximum superelevation. 4. See Table 4-2 for minimum stopping sight distance and K values for vertical curves. 4. 1 . 3 Design Speed Weld County requires designers to use a design speed that is 10 miles per hour ( mph ) above the required posted speed limit . Any change to the existing posted speed limit on a County road requires review by the Public Works Department and approval by the BOCC . To determine an appropriate speed limit, traffic investigations should consider the following factors applicable to the portion of road being studied : • Vehicle speed data ( 85th percentile ) • Crash history • Hazardous locations ( curves, sight distance, etc . ) • Parking practices WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 121 • Roadside development • Road characteristics The enforceable speed limit on roads within the County ( not including roads within a subdivision ) is 55 mph unless posted otherwise or within business districts, residential areas, or other areas where special conditions require a lower speed limit . Section 42 -4- 1102 of the Colorado Revised Statutes requires that speed limits not be higher or lower than the basic prima facie ( reasonable and prudent under normal conditions) speed limit unless a traffic investigation has justified the change . Posted speed limits for roads within subdivisions shall be as follows : • 50 mph for arterial roads; • 40 mph for collector roads; • 30 - 40 mph for local commercial/industrial uses; and • 25 — 30 mph for local residential uses . 4. 2 HORIZONTAL ALIGNMENT 4. 2 . 1 Horizontal Curves Horizontal alignment of the roadway is critical for safe and economical operation of motor vehicles traveling the roadway at the design speed . Horizontal curve design should be based on an appropriate relationship between design speed , right-of-way, profile grades, and construction costs — and on their joint relationships with superelevation and side friction . Curves are not required when the deflection angle ( A ) ( total central angle of the circular curve ) is less than 1 degree . Curves should be at least 500 feet long for a deflection angle of 5 degrees, and the minimum length should be increased 100 feet for each 1 degree increase in the deflection angle . Figure 4- 1 illustrates a simple horizontal curve . Figure 4-1 Horizontal Curve Point of Intersection (PI) Deflection Angle (A) Tangent 1Extetnai Distinct E) ar Length of Curve ( L) Point of Tangency ( PT) .rr r L Point of Curvature (PC ) Simple Curve The formulas can be found in AASHTO' s A Policy on Geometric Design of Highways and Streets and CDOT' s M&S Standard Plans . Minimum radius values may also be taken from the AASHTO superelevation tables, using the " NC" ( normal crown ) line item . For rural areas, use the AASHTO table for minimum radii normal crown rates with emax = 6 percent . For urban areas, use the AASHTO table for minimum radii for normal crown rates with emaX = 4 percent . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 122 Designers should use every effort to exceed the minimum curve radius recommended by AASHTO when practical . Simple curves should be used for all roadways . Broken back, compound , or reverse curves are not recommended . The tangent between curves should be sufficient to accomplish the superelevation transitions required for adjacent curves . An additional 50 feet to 100 feet of tangent length , graded as a normal crown , should be provided between the end of the transition out of one curve and the beginning transition into the next for ease of driving . Minimum intersection tangents ( measured from the pavement edge of the intersected road at intersections ) shall be as follows : 200 feet for arterial roadways; 150 feet for collector roadways; and 100 feet for local roadways as illustrated in Figure 4- 2 . Figure 4-2 Minimum Tangent from Intersection MINIMUM TANGENT FROM INTERSECTION r WELD COUNTY ROAD \ EDGE OF PAVEMENT POINT OF CURVATURE (PC) 4. 22 Superelevation Proper design of horizontal curves often requires the use of superelevation ( roadway banking ) . Factors controlling the use of superelevation include climate conditions, terrain conditions, classification of the road , and the frequency of slow- moving vehicles on the roadway . In general , a lower rate of superelevation is used in urban areas than in rural areas . For rural areas, use the AASHTO table for minimum radii for design superelevation rates with emax = 6 percent . For urban areas, use the AASHTO table for minimum radii for design superelevation rates with emax = 4 percent . If possible , superelevation rates of 4 percent or less should be used in roadway designs . 4. 2 . 3 Transitions The superelevation transition section consists of the superelevation runoff and tangent runout sections . The superelevation runoff is the length of roadway needed to accomplish a change in outside lane cross slope from zero to full superelevation , or vice versa . The tangent runout section is the length of roadway needed to accomplish a change in outside lane cross slope from normal cross slope rate to zero, or vice versa . Additional information pertaining to the lengths and use of transitions for simple and spiral curves can be found in AASHTO' s A Policy on Geometric Design of Highways and Streets and CDOT' s M&S Standard Plans . The design should allow for 60 percent of the superelevation transition length to occur before the horizontal curve starts and after it ends . The remaining 40 percent of the transition occurs within the horizontal curve . This includes the lengths for all the transitions including normal crown , level crown , reverse crown and full superelevation . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 123 4. 2 .4 Cross Slope Cross slope is necessary to ensure adequate roadway drainage . The paved typical cross sections ( described in Chapter 2 of this document ) all show a cross slope of 2 percent, and this is the County' s preferred value for a paved roadway . Non - paved roadways should have a cross slope closer to 3 to 4 percent to help accommodate surface drainage . Undivided roads should have a normal crown that is a two -way cross slope, with the high point of the cross section located on the road centerline . Divided roads should have a cross slope on each side of the divide, with the high point of each section located where the pavement meets the median . Unusual conditions and transition areas may cause the 2 - percent cross slope requirement to vary . Cross slopes varying from a minimum of 1 percent to a maximum of 4 percent may be allowed depending upon surface type . Intersections of roads with curbs and gutters sometimes require the use of crosspans for drainage . At these areas, the normal two -way 2 - percent cross slope will transition to a one -way slope adjacent to the cross pan, with a slope range of 1 percent to 3 percent . For intersections not requiring cross pans, see Figure 4- 3 for the desired cross slope configuration . Figure 4-3 Intersection Cross Slope Detail UNCONTROLLED ---- ---'-� Maintain positive drainage ; INTERSECTION from centerpoint of intersection CONTROLLED ----- ---�'; .x,.._..4.4 to all quadrants. INTERSECTION ---. .,.-- -•~___._•._- ` _..,_. --. � "�-.+--"'ter -..r_.--.. 11� '1 Z•ill t lii . i t . ' . i�..��".--�.% fill i f: \,��W1t� • i : -'�. ~ 1IriIIIl-f 1 ittti it3 ' litilittilliit \ p' f � r • i ' f !t • Mliiiiii 11,1))fthil • .�~ jillill lit= io ''=�-�-_ o or •-:::esa l Through road retains crown • -4=� Eliminate crown from all ev --m'1, side roads with stop/yield signs ; directions approaching --. are shaped to match the edge --'..z the intersection. -�, of through road. y: , �' ems : The rate of change for cross slope in an area of transition , should not exceed 1 . 5 inches over a 50-foot horizontal distance . This rate helps to ensure ride quality for the traveling public . 4. 3 VERTICAL ALIGNMENT Weld County' s topography generally is flat with gentle slopes, but some areas have steep drainage basins and rolling hills . When designing roadway vertical alignment, designers must consider stopping sight distance requirements for the given speed limit and the challenges of large cut-and -fill sections . Vertical curves are classified as either sag or crest curves . Typically, sag curves are controlled by nighttime driving conditions with headlight visibility restrictions, and crest curves are controlled by stopping sight distances . Vertical curves should be simple in application and should result in a design that is safe and comfortable in operation , aesthetically pleasing, and adequate for drainage — especially when a curb and gutter are used . 4. 3 . 1 Maximum and Minimum Grades Grade lines typically are controlled by topography and structure clearances, but very flat grade can be controlled by drainage considerations . Other factors that should be considered are road classifications, design speed , safety, and construction costs . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 124 A minimum grade value of 0 . 4 percent is preferred for road sections with curbs and gutters . In certain conditions, a grade as low as 0 . 3 percent may be used with approval of the Department of Public Works . The designer must consider the ultimate design of the roadway, however, recognizing if a curb and gutter may be required in the future, and then design for those conditions during the interim design . Maximum allowable grades are as identified in Table 4- 1 above; 5 percent on arterials, 6 percent on collectors, and 8 percent on local roads . Grades of 4 percent or steeper will require special consideration for drainage or erosion protection . When using combinations of horizontal and vertical curves, it is important to recognize the driver' s perspective . Sharp horizontal curvature should not be introduced at or near the top of a pronounced crest vertical curve . If unavoidable, the horizontal curve should be made longer than the vertical curve to help minimize the driver' s inability to perceive the horizontal change , especially at night . For further details, see AASHTO' s A Policy on Geometric Design of Highways and Streets and CDOT' s Roadway Design Guide . The length of vertical curves can be determined by dividing the rate of vertical curvature by the grade change or algebraic difference in intersecting grades ( % ) . L ( Length ) ( ft) = K ( rate of curvature ) / A ( grade change ) ( % ) A vertical curve is not required when a grade change or the algebraic difference is ≤ 0 . 2 percent . The Weld County preferred minimum length of a vertical curve is 300 feet . The allowed minimum is three times the roadway design speed . 4.4 SIGHT DISTANCE At intersections, accesses, and points along County roadways, sight distance is essential to protect the traveling public . In evaluating the overall performance of a roadway, there are several sight distances to consider when designing a roadway . When items such as walls, buildings, bridge piers, cut slopes, or vegetation growth are near the roadway on the inside of a curve, they can block a driver' s view of the road ahead . If they are too close, the driver will not have sufficient distance along the curved roadway to stop when a hazardous condition comes into view . Sight distance related to accesses is discussed in Chapter 8 of this document . 4.4. 1 Stopping Sight Distance Stopping sight distance is the length of roadway it takes for a driver to bring a vehicle to a complete stop . Stopping sight distance is measured from the driver' s point of view, which , according to AASHTO' s A Policy on Geometric Design of Highways and Streets, is 3 . 5 feet above the road surface , to an object' s height of 2 feet within the roadway . Stopping sight distance includes the reaction time of the driver and braking distance of the vehicle, as well as roadway grades ( see Table 4-2 ) . Additional information regarding reaction time and braking distance can be found in AASHTO ' s A Policy on Geometric Design of Highways and Streets and in Chapter 8 of this document . As shown in Table 4-2 , stopping sight distance varies depending on the percent in grade up or down within the vertical curve . The designer should account for the varying grades within his or her profile design and select the appropriate values of stopping sight distance . Table 4-2 lists stopping and passing sight distances for various percent grades up or down . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 125 Table 4-2 Stopping and Passing Sight Distances and K Values Design Stopping Sight Distance (feet) Passing Sight Distance Speed No % Down Grade % Up Grade Crest Sag Crest Curve ( mph ) Grade (0) 3 6 9 3 6 9 K K (feet) K 25 155 158 165 173 147 143 140 12 26 450 72 30 200 205 215 227 200 4 184 179 19 37 500 89 35 250 257 271 287 237 A 229 222 29 49 550 108 40 305 315 333 354 289 278 269 44 64 600 129 45 360 378 400 427 344 331 320 61 79 700 175 50 425 446 474 507 405 388 375 A 84 96 800 229 55 495 520 553 593 469 450 433 114 115 900 289 60 570 598 638 686 538 515 495 151 136 1, 000 357 65 645 682 728 785 612 584 561 193 157 1, 100 432 For horizontal curves ( see Figure 4-4), the sight line is measured along the chord of the curve, while the stopping sight distance is measured along the centerline of the inside lane around the curve . Figure 4-4 Horizontal Sight Distance rim Sight Distance Highway CL y — -- — — — _ e � ..—"" HSO � � � .. � I I Line of Sight Sight Obstruction tor. G s Of! o'0 HSO = R( 1-cos ( 28 . 65S/ R ) ) or S = R/ 28 . 65 acos ( ( R- HSO )/ R ) HSO = Horizontal Sightline Offset S = Stopping sight Distance R = Radius of lane centerline Horizontal sight distance may be restricted by obstacles along the roadway or even by cut slopes through a hillside . Other normal roadside objects, such as guardrail , concrete barriers, and privacy fences, should be studied for interference with sight distance . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 126 Vertical sight distance is determined by the geometrics of the curve . Figure 4-5 is an example of the crest vertical curve . Figure 4-5 Crest Vertical Curve sight Distance (S) 3.5ft _# 2 ft (Th Length of Curve ( I ) Sag vertical curves usually are controlled by headlight distance . Under certain conditions, the minimum stopping sight distance values used for design exceed the length of visible roadway . This is because of the limitations of vehicle headlights, especially low- beam headlights . Formulas to determine stopping sight distance on both crest and sag curves can be found in AASHTO's A Policy on Geometric Design of Highways and Streets . 4.4.2 Passing Sight Distance Passing sight distance is the length of roadway required for the driver of a vehicle to pass another vehicle safely and comfortably, without interfering with the speed of an oncoming vehicle traveling at the design speed if it came into view after the passing maneuver was started . Passing sight distance is measured from the driver' s point of view, which is to be measured at 3 . 5 feet above the road surface, to an object' s height of 3 . 5 feet . Typically, passing sight distance will be limited on crest vertical hills . A significant amount of cut may be required to achieve adequate passing sight distance . Table 4-2 lists appropriate passing sight distances for various speeds . 4.4. 3 Decision Sight Distance The stopping sight distances shown in Table 4-2 are distances for reasonable and alert drivers to come to a complete stop . They do not include the time it takes drivers to make a decision when unexpected or unusual maneuvers are required . Decision sight distances ( see Table 4-3 ) are substantially greater than stopping sight distances . Locations where these kinds of decisions are required include interchanges, cluttered or confusing intersections, and short lane drops . ( See AASHTO A Policy on Geometric Design of Highways and Streets for more information . ) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 27 Table 4-3 Decision Sight Distance Decision Sight Distance Decision Sight Distance for Avoidance Maneuver (ft) Design Speed ( mph ) A B C D E 30 or less 220 490 450 535 620 40 330 690 600 715 825 50 465 910 750 890 1, 030 60 610 1, 150 990 1, 125 1, 280 70 780 1, 410 1, 105 1, 275 1, 445 Where: Avoidance Maneuver A = stop on rural road (t = 3. 0 seconds) Avoidance Maneuver B = stop on urban road (t = 9. 1 seconds) Avoidance Maneuver C = speed/path/direction change on rural road (t = 10. 2 sec to 11 . 2 sec) Avoidance Maneuver D = speed/path/direction change on suburban road (t = 12. 1 sec to 12. 9 sec) Avoidance Maneuver E = speed/path/direction change on urban road (t = 14. 0 sec to 14. 5 sec) 4.4.4 Intersection Sight Distance There are numerous intersections within Weld County; most are controlled , but some are uncontrolled , which means there is no signing in either direction . Ideally, intersections would have adequate sight distance in all directions and along approaches to allow drivers to see obstructions or approaching vehicles . However, many of the County intersections do not have unobstructed views for various reasons . Utility appurtenances, embankments, vegetation , and privacy fences are just a few examples of sight restrictions . In these circumstances, and where no traffic control devices are present, the basic rule of the road is the vehicle on the left is to yield to the vehicle on the right if they arrive at about the same time . If drivers cannot see due to sight obstructions at the intersection , it is the responsibility of every driver to slow down and determine if it is safe to continue through the intersection . Additional information regarding intersection sight distance can be found in AASHTO' s A Policy on Geometric Design of Highways and Streets . The recommended dimensions of the sight triangles vary with the type of control used at the intersection because different types of control impose different constraints on drivers and , therefore, result in different behavior. AASHTO' s A Policy on Geometric Design of Highways and Streets presents procedures to determined sight distances at intersections for the following types of traffic control : 1 . Intersections with no control 2 . Intersections with stop control on the minor road 3 . Intersections with yield control on the minor road 4 . Intersections with traffic signal control 5 . Intersections with all -way stop control 6 . Left turns from the major road 7 . Roundabouts Figure 4-6 below, illustrates an intersection with stop control on the minor road . For information regarding the variable definitions and equations used to calculate these distances, see Section 8 . 6 . 2 of this document and AASHTO' s A Policy on Geometric Design of Highways and Streets. WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 128 Figure 4-6 Departure Sight Triangles at Intersection (Stop Control ) o Ow- L b ►♦ Major Road Major Road L— I a " ` Clear Sight Triangle Clear Sight Triangle - g g ri Decision Point Decision Point Departure Sight Triangle for Viewing Traffic Departure Sight Triangle for Viewing Traffic Approaching the Minor Road from the Left Approaching the Minor Road from the Right Private accesses need to take into consideration these sight distance requirements just as other roadways would . More information regarding access sight distance can be found in Chapter 8 of this document . 4. 5 INTERSECTIONS By definition , an intersection is the location where two or more roadways meet or join together. This occurs at at-grade crossings, interchanges, or grade separations without ramps . All of the County-owned intersections in Weld County are at-grade intersections . Generally, there is more potential for conflict at intersections than on straight sections of roadway, so intersections usually have higher accident rates . Chapter 9 of AASHTO' s A Policy on Geometric Design of Highways and Streets discusses intersections and provides guidance on design details . Designers also should refer to CDOT' s Roadway Design Guide . The sections below highlight a few key aspects of intersection design . See also Chapter 2 of this document for typical cross-section drawings . 4. 5 . 1 Alignment and Profile It is very important for the success and safety of any intersection that it is aligned with the intersecting roadway . For standard , at-grade, four-way intersections and T- intersections, the roadways should meet as close to perpendicular as possible . Skewed intersections are difficult for drivers and create unsafe conditions . The required angle between centerlines of the intersecting roadways is 90 degrees, as shown in Figure 4-7 . Any deviations from 90 degrees will need to be approved by the Department of Public Works . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 129 Figure 4-7 Typical Intersections I I 90 Degrees t.I l 2 Rdwy CL 1 — — r- - - T RdwyCL i tv l I 90 Degrees 90 Degrees I i I Four-Way Intersection T Intersection The alignments and grades of the intersecting roadways should permit the maneuvers needed for cars to pass through the intersection with minimal interference . Alignments should be as straight and flat as practical , and substantial grade changes should be avoided . All lanes shall be in general alignment through each intersection ; however, a maximum 2 -foot shift is allowed across an intersection without a variance approval by the County Engineer. The profile grade lines should be adjusted back a distance from the intersection to provide a smooth transition . It may be desirable to remove the cross slopes coming into the intersection , as steep cross slopes or grade changes create an undesirable bump at the intersection and may require reconstruction to correct . Refer back Figure 4-3 for an intersection cross slope detail . A smooth transition is particularly important at intersections where drivers do not reduce their speed or come to a stop . Designers should remember that intersections which are currently stop-controlled may not be stop-controlled in the future . 4 . 5 .2 Corner Radii Corner radii are another critical aspect of intersection design . Corner radii are selected based on the turning radii of different design vehicles . Chapter 2 of AASHTO' s A Policy on Geometric Design of Highways and Streets discusses design vehicles and their different turning radii . The four classes of design vehicles are : passenger cars, buses, trucks, and recreational vehicles . The Weld County design vehicle is the WB-67 truck . 4. 5 . 3 Approval Requirements Chapter 9 of AASHTO ' s A Policy on Geometric Design of Highways and Streets summarizes the minimum edge of traveled way design for the four classes of design vehicles . Usually, the simplest curves to construct are the simple curve with taper and the three -centered compound ( symmetric ) radii . Other compound curves can be difficult to implement in the field . For intersections on arterial and collector roadways, designers should consider a minimum radius of 65 feet, following a simple curve with taper WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G r 130 radii . This allows larger trucks to make right turns without the rear tires going off the road and without veering into opposing vehicle paths . An exhibit from AutoTURN software or equivalent roadway design turning template software must be provided to the County to demonstrate the corner radius is appropriate . 4 . 5 .4 Auxiliary Lanes See Chapter 8 of this document for information on auxiliary lanes . 4. 6 CUL- DE - SACS Cul -de -sacs and dead -end roadways are not common in the County but are sometimes found in subdivision and residential areas . Cul - de -sacs should be designed with a radius large enough to allow a standard fire truck to use the cul -de - sac to make a u -turn without having to back up . The minimum outside curb or pavement edge radius allowed for a cul -de - sac is 55 feet . The minimum right-of-way turnaround radius is 65 feet . The maximum cul -de -sac length between intersecting streets ( from centerline to centerline ) is 1 , 500 feet . No more than 20 lots may be served by a permanent cul -de- sac . The most common design is a circular cul -de -sac with or without a center island . Chapter 5 of A Policy on Geometric Design of Highways and Streets offers additional design criteria and other types of cul -de - sacs . The designer must consult the relevant fire protection authority for its minimum criteria as well . 4. 7 BRIDGES This section is not intended to cover bridge design in detail . It covers only general guidelines . More detailed bridge design information can be found in the latest editions of AASHTO' s LRFD Bridge Design Specifications, the Culverts and Bridges chapter in the USDCM , Volume 2 , and CDOT' s Drainage Design Manual and Bridge Design Manual, as updated . 4. 7 . 1 Bridge Hydraulic Capacity During preliminary design , the designer shall complete a hydrologic and hydraulic analysis of the waterway to correctly size the opening of a new bridge, coordinating with owners as necessary . Bridges over canals require less hydrologic analysis than bridges over natural drainage ways . Designers shall gather and analyze background information , such as past inspection reports, measurable high -water marks, past maintenance issues, scour, and flood records . The storm design frequency for the different types of roadways and drainage types is shown in Table 4-4 . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 131 Table 4-4 Design Frequencies Drainage Type I Design Frequency Multi-Lane Roads Urban area 100-year Rural area 100-year Two- Lane Roads Urban area 100 -year Rural area Qso > 4000 cfs 50-year 050 < 4000 cfs 25 -year Drainage Type Design Frequency Bridge foundation scour Based on Qdesign if: 025 requires Qso scour design and Q1oo Check Flood Qso requires Q1oo scour design and 0200 Check Flood 0100 requires 0200 scour design and Qsoc Check Flood In areas that contain the FEMA mapped 100-year floodplain , designers shall use the 100-year discharge in their designs . If a bridge is being constructed in a 100-year floodplain , all applicable floodplain regulations and codes apply, including the need to submit a Letter of Map Revision ( LOMR ) to FEMA for review and acceptance and the need to obtain a Floodplain Hazard Permit from the County . On wide floodplains, structure loss can be prevented by lowering approach embankments to provide overflow sections that pass unusual floods over the roadway . This may require relief structures to be constructed to allow minor flooding without upstream ponding . Factors such as traffic delays and alternative routes should be considered . Additional and detailed information can be found in CDOT' s Drainage Design Manual and CDOT' s Bridge Design Manual. 4 . 72 Freeboard A minimum clearance, or freeboard , shall be provided between the water surface elevation and the low girder of the bridge . The freeboard is required to allow for wave action , ice, debris, and uncertainty during estimation . The minimum freeboard for a bridge should follow these guidelines : • For a high - debris stream , freeboard should be 4 feet or more . A " high -debris" stream designation often will be site -specific and shall be determined through consultation with Public Works officials and local landowners, as well as through a thorough investigation of the debris potential in the watershed . • For low- to moderate-debris streams, the minimum freeboard will be 2 feet . The water surface elevation at a distance of 50 feet to 100 feet upstream of the face of the bridge will be the elevation to which the freeboard is added to get the low girder elevation of the bridge as a rough estimate of maximum backwater . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 132 4. 7 . 3 Bridge Scour Increased flow velocities at bridge constrictions often lead to scour of the bridge foundations, which can cause the potential for collapse of the structure . Localized bridge scour is comprised of contraction scour and local scour at piers and abutments . These three components are added together to create the final scour envelope . Methodologies for estimating scour at bridges can be found in the following FHWA guidelines : • FHWA, Evaluating Scour at Bridges, Hydraulic Engineering Circular No . 18 ( HEC- 18 ) , latest edition • FHWA, Stream Stability at Highway Structures, Hydraulic Engineering Circular No . 20 ( HEC- 20 ) , latest edition Methodologies for designing scour countermeasures at bridges, piers, and abutments can be found in FHWA' s Bridge Scour and Stream Instability Countermeasures : Experience, Selection , and Design Guidance , Hydraulic Engineering Circular No . 23 ( HEC- 23 ) , latest edition . 4 . 7 .4 Use of HEC - RAS It is acceptable to use the U . S . Army Corps of Engineers ( USACE ) Hydrologic Engineering Center' s River Analysis System ( HEC- RAS ) to determine the hydraulic characteristics at bridges . Standard modeling practices accepted by FEMA should be used when performing HEC- RAS modeling . It is not acceptable to rely on HEC- RAS output for estimating maximum velocities for erosive or hazardous considerations or local scour in a channel . A more-detailed hydraulic analysis of the specific cross section , accounting for variable velocities across the channel, is necessary . 4. 7 . 5 Bridge Railing Bridge railing should be provided along bridge edges to protect both drivers and in applicable situations pedestrians . Weld County follows CDOT M &S Standards for bridge rail and guardrail design . CDOT' s M&S Standard Plans, as well as the CDOT Bridge Structural Worksheets, identify several different railing options and configurations that the designer may consider . AASHTO ' s bridge design documents provide additional information as well . 4. 7 .6 Minimum Structural Requirements Design loadings for bridges shall comply with the latest editions of AASHTO' s LRFD Bridge Design Specifications and CDOT' s bridge design publications . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 133 CHAPTER 5 DRAINAGE CRITERIA 5 . 1 GENERAL The intent of Weld County' s storm drainage criteria WCECC is to protect the health , safety, general welfare, and economic well- being of the County and residents, while also protecting property and infrastructure . The drainage characteristics of Weld County vary greatly throughout the 4, 000 square miles of the county . This chapter aims to provide greater detail on the expectations and guidance for drainage- related portions of a project . Weld County has adopted the following master drainage plans : • South 1 -25 Corridor Master Drainage Plan , also known as "Godding Hollow and Tri-Town Study" ( adopted in 1999 ) . The South 1 - 25 "Tri-Town " Master Drainage Plan from 1999 can be found on the City of Dacono' s website . • Master Drainage Plan for the Area Surrounding Weld County Parkway ( adopted in 2016 ) . This Master Drainage Plan can be found on the County' s Parkway webpage . A map of Weld County' s drainage basins is shown in Figure 5 - 1 . A full -sized version is provided in Appendix A . This manual refers to both the current and older, archived versions of Urban Drainage and Flood Control District ( UDFCD ) Urban Storm Drainage Criteria Manual ( USDCM ) , Volumes 1 through 3 . This manual will explicitly state when to use an older version of the USDCM . UDFCD has rebranded as of 2019 and is now referred to as the Mile High Flood District ( MHFD ) . The MHFD acronym will be used exclusively throughout the chapter. It shall be noted that specifically to drainage, some of these references have provided updated values and equations in recent years that are in accordance with Full Spectrum detention pond design . Weld County does not support Full Spectrum design and , as such , when standards differ, the instructions and guidance in the following Drainage Chapter will govern . All Storm Drainage Guidance documents provided by the County can be found on the Weld County Planning and Zoning ' s Development Review webpage . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 134 Figure 5 - 1 Weld County Watersheds . ..n • - I - ..._- ? y=r M � j • • Y-' r.. .�. �..,. 1 \............t [ \..„, __, ' i kr p...............i..-.. . . f ___,_____ 1 i. . _ _. ,;., \ i 71,,,..±:e . • 1 _ i Land Olin es.VS* —� 3 ...--n, „ , - , . .. . , ,, . 4Y . _„ : . L ! , 7 r ,.. ' 1 I r1ll .! fill. L i. , . •—._, A ._. a ... . li.:a;T_ s # --i. ". a . . - I' 1.-, : li 1 Z. .. !I ' ? ... 1.1 tri_i • 7 au._ 1 . . NII 1 a ._ s_rr—__ -" � - is kaki aleiFir ii » , I �- ( l :i vs 9 us a . ._._tom . . �. . r ,, - .xn - �■� C. �_y'.T. . rt • i sat '.rr_t . .-ill rn . .. - _ . 7I z_ •sly r47. .,; �^ ; �. t ► s:t. ,-�.s• • - _ St in t�.swee.► • - r . _. _ . i . ., .. _ . . . . . •• _00 . 40 a At III. 0- •. 4.1 "%Pr * i t.__ ir■ .. : R r j II Cap t..., i it l+ rr ` b r ,- • . :..__ _....s.__.4 - 471 : - L i i . —. . . - t •S •mot II 'UP _ � -on _ a-- _ o � - .i - �-- _ • � - � � � ��- • i i - Weld County ! „,,,, ' Drainage Basin Map t-- - 'r'�'r' , •� PAO Pt viand Ihr- ems cap,fillie We** tdi 1 •i . "rl�! • ' its legend ►w.,.y7�rtn- ..,... . 3/4:_. .. .,-.5,_ —.a.m. P.. _ ..., . felt Ii P 4f -., j i.1+ • �.vain a. ra. - `• �i-. I •n i i 4 /v ' ; 4rL�.— � A �- - �• z . . . 2 ' ' i n.Oa COLORADO i ,„01-a t isi c.......Vialll • O, flat'- e- l — I . .. • • °. :rlrt P1 11 4,rif I rel .-#' 1 W 0iPPE r -� t Sr) i t ■ �' r w1 t s.„.v.. - •- - ' - ... .a i i t>•. iTL � c • T• � . rL`• t l iF —i wag pas Z i 1 3 4 5W rt 1 FC i 1 4, 1 1 k . L ., ni , 3. r . :rs.t_*rcl• -r .max _ _"II } ...Wrte- i.4.4 r�gt�N ar es .I .•r-♦N �- •-.-- Mr.IMa� -.•...ti,.in 5 . 2 DRAINAGE LAW Refer to the Drainage Law chapter of the USDCM , Volume 1 , for more information on drainage law as it relates to stormwater runoff and floodplain management . 5 . 3 DRAINAGE POLICY The drainage policies set forth are intended to provide adequate stormwater management to preserve and promote the health , safety, general welfare, and economic well - being of the County . Weld County embraces the basic principles defined in the Drainage Policy chapter of the USDCM , Volume 1 . 5 . 3 . 1 Submittal Requirements The Weld County Planning Services Department is the agency responsible for reviewing drainage in the development review process . The submittal requirements for each project ( commercial and residential WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 135 developments, new roadways, new bridges, channel restorations, etc . ) will differ based on the scope and location of the improvements . The Drainage Report Checklist provided in Appendix B shall serve as a guideline for designers throughout the entire design and construction process . The Drainage Report Checklist provides a framework of Weld County' s requirements for the drainage report, construction drawings, and operations and maintenance ( O& M ) plan . The designer shall include this checklist with the preliminary and final deliverables for the project . • The drainage report must fully document all assumptions and methodologies and shall contain copies of all applicable tables and reference materials in an appendix . A drainage basin map shall be included showing basin delineations, flow arrows, design points, pond volumes, and any other information pertinent to the design . • Grading and drainage plans shall be submitted as a single PDF document, printable to scale on 11 - inch x 17 - inch paper. • To assist owners with maintenance , an Operations and Maintenance ( O& M ) plan for stormwater facilities and associated infrastructure shall be included with the final drainage report . The O & M plan should include instructions on safe and correct operations, repair and maintenance of all installed equipment and facilities, and recommended inspection schedules . The O & M plan to be distributed to any applicable homeowners' association or business park association ( or equivalent ) . Weld County has adopted CDOT' s guidelines for the O & M plan and is provided in Appendix C . • Electronic copies of drainage design spreadsheets, models, etc . , may be requested for submittal to Weld County for reviewing purposes . AutoCAD base files ( including site layout, roadways, utilities, survey coordinate system information ) shall be included with the project' s final submittal for inclusion into the County' s GIS mapping system . Electronic pdf copies of all calculations relevant to the design of the project shall be included in the drainage report appendices for review . • Each plan and report must be prepared by or under the supervision of a professional civil engineer licensed to practice in the State of Colorado . Plan sheets will contain the Engineer' s seal ; signed , dated , and sealed per State requirements . Electronic stamps are acceptable . • The report shall contain the Weld County Drainage Code Certificate of Compliance stating that the design meets all applicable drainage requirements set forth in this WCECC, with the exception of County-approved variances . The Certificate of Compliance is available on the Department of Planning and Zoning' s Development Review webpage . Design variance request information is to be included on the lower portion of the Certification of Compliance sheet . The consulting engineer should provide information supporting the variance request in the form of a drainage memo or letter . Any necessary engineering calculations or explanation should be provided in the submittal . • The designer/contractor is to provide an as- built survey, when requested , of the constructed stormwater facilities upon final completion f the project for acceptance by Weld County and issuance of any Certificate of Occupancy . An As- Built Drawing Checklist is included in Appendix D . The survey will be conducted , signed , dated , and sealed by a Professional Land Surveyor licensed to practice in the State of Colorado . At a minimum , the as- built drawings shall include : WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 136 1 . Drawing showing design contours versus as- built contours of constructed pond/site ( 1 -foot contour intervals, labeled ) 2 . Spot elevations at critical drainage design points : • Pond outlet structure • Pond emergency spillway, start and end of riprap or other required protection • Pipe/inlet elevations • Structure inverts • Exposed groundwater elevation , if applicable 3 . Pond design volume ( stage- storage tables ) versus as- built volumes . The designer/contractor shall submit a Statement of Compliance signed and stamped by a Colorado Professional Engineer that verifies in writing that the pond as- built volume meets the design volume requirements . 4 . Drawings shall be properly scaled and sized to clearly show the work that was done through construction . The contractor shall provide signed and stamped Engineered copies of relevant plans and details with updates including the following, but not limited to, updated elevations, dimensions, and pipe sizes . 5 . All appurtenances and related features shall be located horizontally and vertically by the surveyor . Due to a project' s scope and/or location , special permits may be required . Such permits may include construction permits, floodplain permits, and environmental permits . Requirements for special permits are dictated by the approving department or agency . 5 . 3 .2 Data Collection The County uses information and data provided by FEMA, the National Oceanic and Atmospheric Administration ( NOAA ) , the U . S . Geological Survey ( USGS ) , private consulting engineers, and the Colorado Water Conservation Board ( CWCB ) . Before commencing design of any drainage project, designers should collect and evaluate data for the particular watershed area under consideration . Unless explicitly stated otherwise, Weld County will allow the use of data collection methodologies other than what is recommended in this WCECC on a case - by- case basis when complete documentation of all assumptions is provided . Weld County reserves the right to review alternatives and compare with other commonly used approaches, including those discussed in the USDCM . 5 .4 RAINFALL The designer should use the most appropriate and best available data for the project area in determining the rainfall quantities . Local rainfall data shall be obtained from NOAA Atlas 14 : Precipitation -Frequency Atlas of the United States, Volume 8 ( Atlas 14 ) unless otherwise approved by the Department of Public Works, or unless otherwise specified in urbanized jurisdictions and existing master plans . The use of synthetic rainfall distribution data is not permitted . 5 .4. 1 . 1 Intensity Duration Curves for Rational Method To develop depth -duration curves or intensity-duration curves for the Rational Method of runoff analysis, the 1 - hour depth ( s ) obtained from NOAA Atlas 14 can be applied to Equation 5- 1 below for the duration ( or durations ) of interest : WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 137 _ 28 . 5P1 / - Eq . 5 . 4 . 1 ( 10 + Td ) 0 . 86 Where : • 1 = rainfall intensity ( inches per hour) • P1 = 1 - hour point rainfall depth ( inches ) • T1 = storm duration ( minutes ) For more details regarding the development of rainfall information , refer to the Rainfall chapter of the USDCM , Volume 1 . 5 . 5 RUNOFF For more details regarding the development of runoff information , refer to Chapter 8, Article XI, of the Weld County Code and the Runoff chapter of the USDCM , Volume 1 . The County explicitly uses the 2007 version of the Runoff chapter of USDCM , Volume 1 and , as such , it has been made available on the Weld County website . Depending on the size and location of a project, there are three allowable stormwater runoff calculation methods . Table 5 - 1 below summarizes the allowable methodology . When designing a site with multiple detention basins in parallel or series, the use of Stormwater Management Model ( SWMM ) is required for routing . Weld County does not allow the use of CUHP . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 138 Table 5 -1 Runoff Coefficient Equations for Weld County/2008 MHFD ( HSG -a ) Size of Basin Allowable Runoff Calculation Method Less than 5 acres Rational Method required 5 to 160 Acres Rational Method or SWMM allowable Greater than 160 acres SWMM is required 5 . 5 . 1 The Rational Method The Rational Method is a simplistic method for determining peak runoff from a proposed development or road construction project . It should not be used for basins greater than 160 acres . Refer to the Runoff chapter of the USDCM , Volume 1 provided on the County Website for more information regarding application of the Rational Method . The design engineer shall use the Rational Method to perform runoff calculations ( for basin sizes under 160 acres ) . The spreadsheet used to perform runoff calculations, UD- Rationalv1 .02, is available for download on the Department of Public WorksZoning' s Development Review webpage . This spreadsheet utilizes the rational method "C-values" from the 2007 design manual ( shown in Table 5 -3 through Table 5 - 5 below ) . The design consultant may use the downloadable spreadsheets or may create their own based on the information provided in the following portion of this document . The created spreadsheets must use the older 2007 C-values to be accepted . A copy of these runoff coefficients are provided in Appendix E and on the Department of Planning and Zoning' s Development Review webpage . The rational formula is as follows : Q = CxIxA Eq . 5 . 5 . 1 Where : Q = peak runoff rate, cfs C = runoff coefficient, dimensionless I = rainfall intensity at the time of concentration , in/hr A = area of the basin , acres The runoff coefficient, C, represents the effects of infiltration , evaporation , retention , and interception and is calculated based on the soil type and impervious percentages . Higher impervious percentage values ( roofs, parking lots ) mean the area does not readily allow water to infiltrate into the ground , whereas lower impervious percentage values ( parks, green space ) mean the area does allow water to infiltrate into the ground . The recommended impervious percentage values, I , for Weld County are provided in Table 5 - 2 , below . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 139 Table 5 -2 Percentage Impervious Values for Weld County Land Use or Surface Characteristics Percent Impervious (%) Commercial 95 Residential : Si -igle - Family Greater than 2 . 5 acres or larger 12 Greater than 0 . 75 acre to 2 . 5 acres 20 Greater than 0 . 25 acre to 0 . 75 acre 30 0 . 25 acre or smaller 45 Multi - Unit Detached 60 Multi - Unit Attached 75 Apartments 80 Industrial : Light 80 Heavy 90 Solar Facilities: A & B Soils 2 C & D Soils Site-specific Parks, Cemeteries 10 Playgrounds 25 Schools 55 Railroad Yard Areas 50 Roos 90 Undeveloped Areas: Historic Flow Analysis 2 Greenbelts, Agricultural 2 Streets: Paved 100 Packed Gravel ( Includes Road Base and Compacted , 40 Cleared, Earthen Areas typically used for Roads/ Parking/Storage ) Recycled Asphalt Pavement 75 Drives and Walks 90 Table 5 -3 through Table 5 -5 use the impervious percent value ( expressed as a decimal ) to calculate the runoff coefficients for Natural Resources Conservation Service ( NRCS ) hydrologic soil groups A, B, and C/ D for various storm return periods . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P AC 17 140 Table 5 -3 Runoff Coefficient Equations for Weld County/2007 MHFD ( HSG-A) Hydrologic Soil Group A 5-Year 10-Year 100-Year Equation Cs = (-0.08i + 0.09) + Cio = (-0. 141 + 0. 17) + Cioo = (-0.25i + 0.32) + ( 1.31i3 - 1 .44i2 + 1. 135i ( 1.31i3 - 1 .44i2 + 1 . 1351 ( 1.31i3 - 1 .4412 + 1 . 135i - 0. 12) - 0. 12) - 0. 12) 2% 0.00 0.07 0. 22 5% 0.02 0. 10 0 . 24 10% 0.06 0. 14 0 . 28 15% 0. 10 0. 17 0 . 30 20% 0 . 13 0. 20 0. 33 25% 0. 16 0. 23 0. 35 30% 0. 19 0. 25 0. 37 35% 0. 22 0. 28 0.39 40% 0 . 25 0. 30 0.41 45 % 0. 27 0. 33 0 .43 50% 0 . 30 0.35 0 .45 55% 0 . 33 0. 38 0 .47 60% 0. 37 0.41 0. 50 65% 0 .41 0.45 0. 53 70% 0 .45 0.49 0 . 56 75% 0. 50 0. 54 0 . 61 80% 0. 56 0. 60 0. 66 85% 0. 63 0. 66 0. 72 90% 0. 71 0. 73 0. 79 95% 0.80 0.82 0.86 100% 0. 90 0.92 0.96 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 141 Table 5-4 Runoff Coefficient Equations for Weld County/2007 MHFD ( H5G -B ) Hydrologic Soil Group B Equation 5-Year 10-Year 100-Year Cs = (Ca + Ccd)/ 2 Clo = ( Ca + Ccd)/ 2 Cioo = ( Ca + Ccd)/ 2 2 % 0 . 08 0 . 17 0 . 36 5% 0 . 10 0 . 19 0 . 38 10% 0 . 14 0 . 22 0 . 40 15 % 0 . 17 0 . 25 0 . 42 20% 0 . 20 0 . 27 0 .44 25 % 0 . 22 0 . 30 0 .46 30% 0 . 25 0 . 32 0 .47 35 % 0 . 27 0 . 34 0 .48 40% 0 . 30 0 . 36 0 . 50 45% 0 . 32 0 . 38 0 . 51 , 50% 0 . 35 0 . 40 0 . 52 55 % 0 . 38 0 . 43 0 . 54 60% 0 . 41 0 . 46 0 . 56 65 % 0 .45 0 . 49 0 . 59 70% 0 . 49 0 . 53 0 . 62 75% 0 . 54 0 . 58 0 . 66 80% 0 . 59 0 . 63 0 . 70 85% 0 . 66 0 . 69 0 . 75 90% 0 . 73 0 . 75 0 . 81 95 % 0 . 81 0 . 83 0 . 88 100% 0 . 90 0 . 92 0 . 96 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 142 Table 5-5 Runoff Coefficient Equations for Weld County/2007 MHFD ( HSG C/ D ) Hydrologic Soil Group C/ D 5-Year 10-Year 100-Year Equation Cs = (-0 . 10i + 0 . 11 ) + C10 = ( -0 . 18i + 0 . 21 ) + C100 = ( -0 . 39i + 0 .46) + (0 . 858i3 - 0 . 786i2 + (0 .858i3 - 0 . 786i2 + (0.858i3 - 0 . 786i2 + 0 . 774i + 0 . 04) 0. 774i + 0.04) 0. 774i + 0. 04) 2% 0 . 16 0 . 26 0 . 51 5% 0 . 18 0 . 28 0 . 52 10% 0 . 21 0 . 30 0 . 53 15% 0 . 24 0 . 32 0 . 54 20% 0 . 26 0 . 34 0 . 55 25% 0 . 28 0 . 36 0 . 56 30% 0 . 30 0 . 38 0 . 57 35 % 0 . 33 0 . 40 0 . 57 40% 0 . 35 0 . 42 0 . 58 45% 0 . 37 0 . 44 0 . 59 50% 0 . 40 0 . 46 0 . 60 55% 0 . 43 0 . 48 0 . 62 60% 0 . 46 0 . 51 0 . 63 65% 0 .49 0 . 54 0 . 65 70% 0 . 53 0 . 57 0. 68 75 % 0 . 58 0 . 62 0 . 71 80% 0 . 63 0 . 66 0 . 74 85 % 0 . 68 0 . 71 0 . 79 90% 0 . 75 0 . 77 0 . 83 95 % 0 . 82 0 . 84 0 . 89 100% 0 . 90 0 . 92 0 . 96 5 . 5 . 1 . 1 Time of Concentration The time of concentration is calculated based on the length , slope , and cover in the basin . The time of concentration is calculated by adding the initial or overland flow time and the channelized travel time . tc = ti tt Eq . 5 . 5 . 1 . 1 Where : tc = Time of concentration , minutes ti = Initial or overland flow time, minutes tt = Channelized travel time, minutes 5 . 5 . 1 . 2 Initial or Overland Flow Time The initial or overland flow time will be calculated as follows : WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA 143 0 . 395 ( 1 . 1 - 05 ) Xi ti = 0 Eq . 5 . 5 . 1 . 2 So .33 Where : L; = Length of overland flow, ft ( 500 ft maximum for non - urbanizing undeveloped areas, 300 ft maximum for urbanizing or developed areas ) So = Overland basin slope, ft/ft 5 . 5 . 1 . 3 Channelized Flow Time The channelized flow time ( travel time ) will be calculated as follows : Lt t = = Lt Eq . 5 . 5 . 1 . 3 t 60Ky/Sa 60V Where : Lt = Waterway length , ft So = Waterway slope , ft/ft K= NRCS Conveyance Factor ( see Table 5 - 6 ) V= Travel time velocity, ft/s Table 5-6 NRCS Conveyance Factor, K Type of Land Surface NRCS Conveyance Factor Tillage/Field 5 Short pasture and lawns 7 Nearly bare ground 10 Grassed waterway 15 Paved areas and shallow paved swales 20 5 . 5 . 1 .4 Urban Check For developed and urbanizing basins, the maximum time of concentration shall not exceed the time of concentration calculated by the urban check equation as follows : t = Lt 10 Eq . 5 . 5 . 1 .4 180 Where : lit = Waterway length , ft The minimum time of concentration for urbanizing areas is 5 minutes and the minimum time of concentration for non - urbanizing areas is 10 minutes . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G Fi: J 44 5 . 5 . 2 Larger Basin Rainfall Methods Based on Table 5 - 1 , areas larger than 160 acres require use of the SWMM , developed by the Environmental Protection Agency ( EPA) . The designer should use the most up-to-date version of SWMM . Any supporting modeling data should be included in the drainage report appendices, so that review staff can adequately review the model . Supporting documentation should include basin information , infiltration method used ( with supporting coefficients, curve numbers, soil types ) , rainfall data , stage- storage curves for ponds and any other pertinent information for the model . Electronic submittals of the SWMM model are required with each submittal package for review by County staff. 5 . 6 ROADS, INLETS, AND STORM DRAINS Stormwater collection and conveyance systems ( roads, inlets, and storm drains ) for new developments shall be designed to convey the 100-year storm event to the proposed detention/retention pond . Street flooding may occur, in which case traffic is disrupted as the street functions as an open channel ( see Secticn 5 . 8 ) . In these cases, the design engineer shall ensure that any flooding or surcharge of the system shall maintain public safety, minimize flood damages, and allow for emergency vehicle access as required by the local agency . Sizing of inlets, pipe systems, culverts or other drainage collection systems on private development sites should be designed to safely convey flows through the site, in a manner that will protect the site' s users from harm and will not cause damage to on -site structures . The design engineer for the project shall provide calculations for pipe sizes, overtopping of roads, ditches, etc . , such that the County' s review engineers can verify that the drainage on -site is safe for users . The County reserves the right to comrrent on private drainage systems that they see as being unsafe or inadequate for the intended site use . The 100-year developed flows must be transported safely to the site' s detention pond for a controlled release . For in=ormation regarding the design of stormwater collection and conveyance systems, refer to Chapter 8, Article XI, of the Weld County Code and the Streets, Inlets, and Storm Drains chapter of the USDCM , Volume 1 . 5 . 6 . 1 Applicable Software It is acceptable to use HydroFLOW, CivilStorm , HY-8, FlowMaster, and StormCAD softwares to determine the hydraulic characteristics of storm networks/culverts . Inlet spread calculations and street capacities with curb and gutter to be analyzed using newest version available of MHFD' s UD- Inlet spreadsheets provided on their website . Alternative modeling software may be used upon approval by the Department of Public Works . 5 . 6 .2 Roadway Drainage Roadway classifications in Weld County are described in Section 2 . 1 of this WCECC and include freeways ( interstates ), county highways, arterials, collectors, local roads, and privately maintained roads . For collector roads, local roads, and privately maintained roads, the maximum encroachment depth over the roadway crown is 6 inches during the 10-year storm and 18 inches during the 100-year storm . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 145 Allowable roadway overtopping for interstates, county highways, and arterials shall be determined by the Public Works Director or Designee . 5 . 6 . 3 Inlets The design guidelines provided in the Streets, Inlets, and Storm Drains chapter of the USDCM , Volume 1 should be used when designing stormwater inlets . In general , the allowable road capacity and maximum encroachment depth shall dictate the placement of inlets . Inlets should be placed at low points ( sumps ) , median breaks, intersections, super-elevation transitions, and before cross walks and bridges, as required . The standard inlets permitted for use in Weld County streets and roads are shown in Table 5-7 . Weld County has adopted CDOT (Type C, Type D, Type R and Type 13 ) and Greeley ( Combination Type 3 ) Inlet detail , with modifications as provided in details sheets . See Appendix J . Note : Inlet Types C and D will require close mesh grates as directed by Weld County . Table 5-7 Inlets for Weld County Inlet Type Permitted Use Curb Opening Inlet Type R All street types with 6-inch vertical curb Grated Inlet Type C, D Roadside ditches or swales Grated Inlet Type 13 Alleys or private drives with a valley gutter Combination Inlet Type 3 All street types with 6-inch vertical curb Various factors, such as debris clogging, pavement overlaying, and variations in design assumptions can decrease the capacity of inlets . To account for these factors, Weld County recommends that the theoretical capacity calculated for inlets be reduced by the factors presented in Table 5 -8 . Table 5 -8 Theoretical Capacity of Inlets for Weld County Percent of Theoretical Condition Inlet Type Capacity Allowed Sump or continuous grade Curb Opening Type R ( 5 -ft Length ) 2 88 Curb Opening Type R ( 10-ft Length ) 2 92 Curb Opening Type R ( 15 -ft Length ) 2 95 Continuous grade Combination Inlet Type 3 66 Sump 1Grated Inlet Type C or D2 50 Grated Inlet Type 132 50 - Combination Inlet Type 3 65 1 Type C and D inlets shall not be placed in roadways 2 CDOT Standards, with modifications 5 . 6 .4 Pipes The design guidelines provided in the Streets, Inlets, and Storm Drains chapter of the USDCM , Volume 1 should be used when designing stormwater pipes . Pipe networks shall be sized to convey the 10-year WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 146 storm event while flowing at 80 percent of the full pipe capacity . In the 100-year event, the hydraulic grade line ( HGL) shall be kept at least one foot below manhole lids, inlet grates, and inlet curb openings . The calculated HGL for both the minor and major storm events shall be provided on all proposed final storm profile views . The minimum flow velocity ( for both storm events ) shall be 3 ft/s to minimize sediment deposition . Maximum flow velocity (for both storm events ) shall not exceed 18 ft/s to minimize scour at the outlet . Erosion protection at the pipe outlet is required for all velocities greater than or equal to 3 ft/s . Riprap should be used at pipe outlets and have a minimum D50 of 9 inches (Type L) . The minimum allowable size for a storm sewer within a public right-of-way or public drainage easement shall be 15 inches in diameter or equivalent . The Department of Public Works should be contacted to determine which types of storm sewer pipes are permissible for use in public rights of way or public drainage easements . Pipes constructed under the travel lanes of a new public roadway shall be reinforced concrete pipe ( RCP ) , Class 3 strength or greater, depending on traffic loading, or an approved equivalent . All RCPs shall have a minimum cover of 12 inches above the pipe crown and bell to the bottom of pavement section ( asphalt or concrete ) at the edge of the roadway . A minimum of 12 inches of cover above the pipe crown to the top of the finished grade is required for gravel roads . If 12 inches of cover is not possible, the pipe material must be rated for a minimum of HS- 20 loading or the largest expected loads crossing it ( i . e . , oil rigs, semi-trucks, etc . ) . The contractor must provide shop drawings for any precast concrete box culvert ( CBC ) to be approved for use by the engineer. The Manning' s roughness coefficient " n " for all storm sewer capacity calculations in Weld County shall be 0 . 013 regardless of pipe material ( e . g . , concrete , polyvinyl chloride [ PVC] , or high -density polyethylene [ HDPE ] ) — with the exception of aluminized corrugated metal pipe ( CMP ) , which shall have a coefficient of 0 .025 . However, the designer should take note that only RCP and CMP are allowed in public ROW due to ditch burning . Any other pipe material used shall only be placed outside of public ROW, or upon approval by the Department of Public Works . 5 . 6 . 5 Manholes Manholes shall be provided to allow for inspection and maintenance of stormwater systems . At a minimum , manholes shall be placed at all pipe junctions, changes in pipe size or material , and changes in grade and alignment . For long straight runs of pipe, the distance between manholes shall be limited to 400 feet ( for pipe diameters < 42 inches ) and 500 feet (for pipe diameters ≥ 42 inches ) . Manhole lids shall not be located within the vehicle wheel path . Table 5-9 Manhole Sizes Storm Pipe Diameter ( inches) Manhole Diameter (ft) 15 inches to 18 inches 4 ft 21 inches to 30 inches 5 ft 36 inches to 54 inches 6 ft 60 inches + CDOT Standard M -604 - 20 It shall be noted that the designer should review the incoming and outcoming pipe angles to ensure that the manhole diameter can accommodate the pipe skew, when the pipe sewer alignment is not straight WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 147 through , or when more than one sewer line goes through the manhole . Steps shall be provided to allow safe access into the manhole . Manhole details are provided in Appendix J 5 . 7 OPEN CHANNELS, ROADSIDE DITCHES, AND GRASS SWALES It is important to distinguish the difference between channels, ditches, and swales . Open channels and grass swales often are existing drainage conveyances that either carry large offsite flows around a site or carry onsite flows to a detention pond on -site . County-owned roadside ditches are common along rural roads and provide runoff conveyance for the County' s roadway infrastructure . Irrigation ditches are not considered to fall under any of these definitions and shall be treated as separate infrastructure altogether. Open channels, grass swales, storm pipe systems, and culverts located on new development sites need to ensure runoff from the developed site for the 100-year storm event can safely reach the on -site detention pond with adequate capacity and freeboard . This can be a combination of overland flow, pipes, or swales to get the runoff to the pond , without it leaving the site . The design engineer needs to provide calculations to show that the 100-year developed flows make it to the pond without overtopping or exceeding the capacity of the proposed drainage system . Any off-site flows that are planned to be routed around the developed site must be designed using a 100-year runoff value, so that no unplanned flows enter the proposed site that were not planned for in the detention pond ' s spillway calculations . Roacway ditches that are designed by consultants for the County ( for County-owned and maintained roadways only) may use a developed runoff from the 10-year, 1 - hour storm event in their ditch designs . For more information regarding the design of open channels, refer to Chapter 8, Article XI , of the Weld County Code and the Open Channels chapter of the USDCM , Volume 1 . Information regarding the design of roadside ditches is provided in the Streets, Inlets, and Storm Drains chapter of the USDCM , Volume 1 . If grass swales are used , they shall be designed in accordance with the Grass Swales Fact Sheet (T-2 ) of the USDCM , Volume 3 . 5 . 7 . 1 Applicable Software The design of open channels, grass swales, and roadside ditches is to be completed in FlowMaster or Hydraflow Express Extension for Autodesk software . Channels, swales, and roadside ditches will be designed to account for any erosive or hazard conditions . It is acceptable to use USACE' s HEC- RAS software to determine the hydraulic characteristics of large open channels . HEC- RAS modeling shall be performed to align with standard modeling practices accepted by FEMA . It is the designer' s responsibility to effectively model erosive , hazard , or local scour in a channel for estimating maximum velocities . The designer shall create a model that adequately places the correct number of cross sections in the necessary locations to accurately make an evaluation of velocities throughout the channel to determine its erosive and scour potential . 5 . 7 .2 Open Channels and Swales Generally, channels and swales should be designed as a trapezoidal shape with a minimum two -foot bottom width and side slopes no steeper than 4 : 1 . If, however, steeper slopes are required due to site WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PA G F 148 constraints, the design engineer should address how the channels will be maintained , since it may not be safe to mow on slopes that are greater than 4 : 1 . The design engineer also should consider the appropriate seed mix and seeding application method when determining side slopes . More information on seed mixes and revegetation can be found in Chapter 6 of this WCECC . Open channels and swales shall be designed to allow the 100-year design flow plus a minimum of one foot of freeboard . However, channels conveying less than 20 cfs may reduce the minimum one-foot freeboard requirement to the freeboard required to convey 1 . 33 times the 100-year design flow . The reduced freeboard may only occur if a one-foot minimum freeboard is not physically possible and calculations are submitted . Hydraulic structures ( check/drop structures, bridges, transitions, constrictions, bends, confluences, rundowns ) associated with open channels shall be designed for the 100-year storm event . For more information regarding the design of hydraulic structures, refer to Chapter 8, Article XI, of the Weld County Code, the most recent version of Hydraulic Structures chapter of the USDCM , Volume 2 , and Chapter 4 . 7 - Bridges of this WCECC . MHFD has published guidelines for typical Manning' s n values and other design criteria for "V" and trapezoidal swales . Table 5- 10 through Table 5 - 12 and Figure 5-2 and Figure 5 -3 below provide guidance for channel design . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G L 49 Table 5 -10 Roughness Coefficients ( " n" ) for Channel Design (After Chow 1959 ) Roughness Coefficients ( n) Channel Type Minimum Typical Maximum I . Excavated or Dredged 1 . Earth , straight and uniform a . Gravel, uniform section , clean 0 . 022 0 . 025 0 . 030 b . With short grass, few weeds 0 . 022 0 . 027 0 . 033 2 . Earth , winding, and sluggish a . Grass, some weeds 0 . 025 0 . 030 0 . 033 b . Dense weeds or aquatic plants 0 . 030 0 . 035 0 . 040 c. Earthy bottom and rubble/riprap sides 0 . 028 0 . 030 0 . 035 3 . Channels not maintained , weeds and brush uncut a . Dense weeds, high as flow depth 0 .050 0. 080 0 . 120 b . Clean bottom , brush on sides 0 . 040 0 . 050 0. 080 II . Natural streams ( top width at flood stage 100 ft ) 1 . Streams on plain a . Clean, straight, full stage, no rifts or deep pools 0 . 025 0 . 030 0 . 033 Clean , winding, some pools and shoals, some 0 . 035 0 . 045 0 . 050 b . weeds and stones Very weedy reaches, deep pools, or floodways 0 . 075 0 . 100 0 . 150 c . with heavy stand of timber and underbrush Ill . Lined or Built- Up Channels 1 . Concrete a . Trowel/float finish 0 . 011 0 . 015 0 . 016 b . Shotcrete 0 . 016 0 . 020 0 . 025 2 . Gravel bottom with sides of: a . Formed concrete 0 . 017 0 . 020 0 . 025 b . Random stone in mortar 0 . 020 0 . 023 0 . 026 c. Dry rubble or riprap 0 . 023 0 . 033 0 . 036 3 . Wetland Bottom Channels See Figure 5 -2 4 . Grass- Lined Channels and Swales See Figure 5 -3 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A CT F 150 Figure 5-2 Manning's n vs. Depth for Low- Flow Section in a Composite Channel . 070 - - . 065 . 060 . 055 r 76 C sw C . 050 • - C C g . 045 ' -_- n = 0 0001 ( Y - ) 0.00250 Y ) + 0.050 . 040 • n = 0.00180i ear - . 035 0.0206(Y) + 0.099 . 030 2 3 4 5 6 7 8 9 10 Depth of Flow Y . in Feet WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF J 51 Figure 5-3 Manning's n vs. VR for Two-Retardances in Grass-Lines Channels 05 - - - - - - - 04 03 Channel capacity design curve 02 . C (C) Retardance 08 Isr , . Z , Z 1 (D) 06 • 2 05 04 /• Limiting velocity 03 design curve 0201 02 03 04 0506 08 10 2 3 4 5 6 8 10 20 30 VR , PRODUCTOF VELOCITYAND HYDRAULIC RADIUS From "Handbook of Channel Design For Soil and Water Conservation, Ll S Department of Agriculture, Soils Conservation Service. No SCS-TP-61 March, 1947, Rev June, 1954 Table 5-11 Trapezoidal Channel Design Guidance/Criteria Criteria for Various Types of Channel Lining Design Item I Grass: Erosive Soils Grass: Erosion Resistant Soils Riprap Concrete 3 .0 ft/sec 5.0 ft/sec 12.0 ft/sec 18.0 ft/sec Maximum 100-yr Velocity Minimum Manning's n - a030 0.030 0.030 0.011 capacity check Maximum Manning's n - 0.035 0.035 0.040 0.013 capacity check 0.5 0.8 0.8 n/a Maximum Froude Number 4H :1V 4H : 1V 2.5H :1V 1.5H : 1V Maximum side slope Minimum centerline radius for 2 x top width 2 x top width 2 x top widtr) 2 x top width a bend Minimum freeboard 1.0 ft .0 ft 1 .0 ft 1.0 ft 5 . 7 . 3 Roadside Ditches The designer shall design flexible ditch linings based on FHWA' s Design of Roadside Channels with Flexible Linings, Hydraulic Engineering Circular No . 15 ( HEC- 15 ) guidelines and should coordinate with the Department of Public Works for approval of the chosen lining . Riprap- lined ditches shall have a minimum D50 of 9 inches (Type L) . Roadside ditches shall be designed to maintain a minimum of one foot of freeboard during the 10-year storm event . Design criteria , provided in the previous Open Channels and Swales section , should be used in the design of roadside ditches as well . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 152 5 . 8 CULVERTS Culverts are structures that convey flow through embankments such as roadways and railroads and should not be confused with storm drainage systems . If a project uses culverts in any facet and connects to County facilities, then the culvert and associated facilities must convey the 100-year storm event flow . A culvert is required for every new access point or supporting documentation must be provided to the County to show that a culvert is not needed . For more information regarding the design of culverts, refer to Chapter 8, Article III, Article XI, and Appendix 8- B of the Weld County Code and the Culverts and Bridges chapter of the USDCM , Volume 2 . See also the latest edition of AASHTO' s Roadside Design Guide . 5 .8 . 1 Applicable Software It is acceptable to use FHWA' s HY-8 or CulvertMaster culvert analysis software to determine the hydraulic characteristics of culverts . Alternative modeling software may be used upon approval by the Department of Public Works . 5 .8 . 2 Sizing Culverts shall be sized such that any roadway overtopping meets allowable street capacity and maximum encroachment depth requirements . The minimum allowable size for a culvert within a public right-of-way or public drainage easement shall be 15 inches in diameter or equivalent . Weld County may require additional culvert capacity to prevent flooding and backwater effects on adjacent properties . The storm drainage system for a developed site, via culverts, inlets, swales, pipe systems, must provide adequate capacity to safely convey the 100-year developed runoff to the site' s detention/ retention pond without leaving the site . If the culvert/pipe system is undersized and results in flooding, the flooding must be contained onsite . It should be shown that on -site flooding does not impact permanent structures or buildings on - site . Developed runoff from the site may not adversely impact adjacent or downstream properties . The maximum overtopping of local or collector County roads during the 10-year storm event is 6 inches and 18 inches in the 100-year event . However, the County prefers to minimize overtopping to the greatest extent possible . Allowable roadway overtopping for county highways and arterials shall be determined by the Public Works Director or Designee . Private culverts/swales within developments must be sized to provide adequate capacity to carry runoff from the 100-year event safely to the proposed detention/ retention pond . Additionally, culverts must be sized to meet the maximum headwater to depth ratios ( HW/ D ) listed in Table 5 - 12 . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 153 Table 5- 12 Maximum HW/D Requirements for Weld County Range of Diameter or Height or Rise ( Inches) Maximum HW/ D Less than 36 inches 2 . 0 36 inches to 60 inches 1 . 7 Larger than 60 inches but less than 84 inches 1 . 5 84 inches to less than 120 inches 1 . 2 120 inches or larger 1 . 0 Culverts shall be installed to the minimum slope required to achieve a minimum flow velocity of 3 ft/s to minimize sediment deposition within the pipe . The slope should be checked for each design , and if the proper minimum velocity is not obtained , other design options should be evaluated . Maximum velocity at the culvert exit should be consistent with the velocity in the channel to which it discharges so as to reduce the risk of scouring at the culvert outlet . Energy dissipators may be required and shall be designed per the most recent version of Hydraulic Structures chapter of the USDCM , Volume 2 , and the guidelines in the FHWA Hydraulic Design of Energy Dissipators for Culverts and Channels, Hydraulic Engineering Circular No . 14 ( HEC- 14 ) . 5 . 8 . 3 Materials Weld County allows the installation and use of commonly available culvert types such as RCP and aluminized CMP within the public right-of-way . Weld County will allow the use of other culvert types on a case- by-case basis when complete documentation of all culvert specifications is provided . It should be noted that pipe materials that do not withstand high temperatures ( burning of roadside ditches ) , should not be used within the County ROW . 5 .8 .4 Cover All culverts must be installed with a minimum of 12 inches of cover above the pipe crown and bell to the bottom of asphalt at the edge of pavement ( for paved roads ) and a minimum of 12 inches of cover above the pipe crown to the top of the finished grade ( for gravel roads ) . If 12 inches of cover is not possible , the culvert material must be rated for a minimum of HS- 20 loading or the largest expected loads crossing it ( i . e . , oil rigs, semi -trucks, etc . ) . 5 . 8 . 5 End Sections and Safety Grate At a minimum , culverts installed in public rights-of-way must be equipped with a flared end section or headwalls on the culvert entrance and outlet, as directed by Public Works . Cutoff walls below the outlet end section shall be 4, 500 psi concrete with epoxy coated #5 rebar 12 " on center each way, three inches clear from all earthen edges, 8" wide x 3 ' deep and 2 ' beyond each outside edge of the end section . There may be situations in which other types of culvert inlets are necessary . In those situations, the design methodologies outlined in the Culverts and Bridges chapter of the USDCM , Volume 2 should be used . Safety grates are strongly recommended at culvert entrances to prevent people , animals, and large debris from inadvertently entering a culvert . Safety grates shall not be placed at the outlet of culverts or storm drains . The following conditions may require use of a safety grate : • It is not possible to see daylight from one end of the culvert to the other . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 154 • The culvert is less than 42 inches in diameter . • Conditions within the culvert ( bends, obstructions, vertical drops ) or at the outlet are likely to trap or injure a person . Exceptions to the above criteria consist of street curb-opening inlets and driveway culverts that are subject to ponding depths no greater than 12 inches at the flowline and culvert entrances that are made inaccessible to the public by fencing . Sound engineering judgement should be used to determine the need for a safety grate while also considering hydraulic forces and clogging potential . Undersized or poorly designed grates can become clogged during heavy runoff and the culvert may be rendered ineffective . Additionally, the surrounding site features and depth and velocity of flow may increase the risk of pinning a human or animal against the grate . To minimize these hazards, safety grates should be sized according to the Outlet Structures Fact Sheet (T- 12 ) of the USDCM , Volume 3 and designed to meet the following criteria : • Grates should be inclined at a slope no steeper than 3 : 1 ( flatter is better) and have a clear opening at the bottom of no more than 9 inches to permit passage of debris and bed load at lower flows . • Weld County does not allow the use of collapsible gratings . 5 .8 .6 Maintenance The County will maintain culverts located within the County ROW . Private property owners are responsible for maintenance of their culverts . Culverts that are part of a subdivision drainage plan are maintained by the respective homeowner' s association . Those culverts should be maintained and cleaned out on an as- needed basis to ensure proper drainage of the subdivision . Safety grates should be inspected and cleaned after every large storm event ( at a minimum ) to ensure that the systems remain effective and that clogging and pinning risks are minimized . 5 . 9 RIPRAP Riprap should be included on the downstream end of culverts and pipe systems to provide erosion protection . The following direction should be used when designing riprap aprons at the outlet of culverts and pipe systems . Mirafi FW-300 or approved equivalent shall be installed under all riprap . 5 . 9 . 1 . 1 Configuration of Riprap Apron Figure 5-4 illustrates typical riprap protection of culverts outlets . 5 .9 . 1 . 2 Extent of Protection The length of the riprap protection downstream from the outlet depends on the degree of protection desired . If it is necessary to prevent all erosion , the riprap must extend until the velocity decreases to an acceptable value . The acceptable major event velocity is set at 3 ft/sec for non - cohesive soils and at 5 ft/sec for erosion resistant soils . The rate at which the velocity of a jet from a conduit outlet decreases is not well known . The procedure recommended here assumes the rate of decrease in velocity is related to 1 the angle of lateral expansion , 0, of the jet . The velocity is related to the expansion factor, 2 tan 0 which can be determined directly using Figure 5-5 or Figure 5- 6 by assuming the expanding jet has a rectangular shape : WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 155 L = 1 At - W Eq . 5 . 9 . 1 2 tan 8 Yt Where : Lp = Length of protection (ft ) W = Width of the conduit ( ft, use diameter for circular conduits ) Yt = Tailwater depth (ft ) 8 = The expansion angle of the culvert flow and : A = Q At Eq . 5 . 9 . 2 V Where : At = required area of flow at allowable velocity (ft' ) V = the allowable non -eroding velocity in the downstream channel ( ft/sec) Q = design discharge ( cfs ) For Eq . 5 . 9 . 1 : • If the tailwater elevation is unknown or unable to be calculated , a value of 0 . 4 x the culvert height or pipe diameter may be used for Yt . 1 • The expansion factor can be found from Figure 5-5 and Figure 5- 6 shown below, after 2tan6 calculating Q/ D2.5 . • In the calculations for At, the allowable non -eroding velocity in the downstream channel should be : o 3 . 0 ft/sec for erosive soils o 5 . 0 ft/sec for non -erosive soils In ce .tain circumstances, Eq . 5 . 9 . 1 may yield unreasonable results . Therefore, in no case should Lp be less than 3H or 3D, nor does Lp need to be greater than 10H or 10D whenever the Froude parameter, Q/WH ' S or Q/ D2-5, is less than 8 . 0 or 6 . 0, respectively . Whenever the Froude parameter is greater than those maximums, increase the maximum Lp required by % Dc or NH for circular or rectangular ( box ) culverts, respectively, for each whole number by which the Froude parameter is greater than 8 .0 or 6 . 0, respectively . Once Lp has been determined , the width of the riprap protection at the furthest downstream point should be verified . This dimension is labeled "T" on Figure 5-4 . The first step is to solve for 0 using the results from Figure 5 - 5 or Figure 5 -6 : 1 0 = tan - 1 Eq . 5 . 9 . 3 2 (ExpansionFactor) Where : • Expansion Factor = determined using Figure 5- 5 or Figure 5 -6 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 156 T then is calculated using the following equation : T = 2 Lptan0 + W Eq . 5 . 9 .4 Figure 5-4 Riprap Apron Detail for Culverts In Line with the Channel ( USDCM, Vol 2 Figure 9-34) EXTEND RIPRAP TO HEIGH T OF PIPE OR BOX. MIN. 05 In la ellerevilecip \n,1/4,..... .. ,ITA.T.IN„.. „..sesir‘. ,. ..._ s , s .AL RN earfil:fia a jibes gobaisb di,*as di dais AI At dirstelliMeil`StratOlFer,a 5 r Aire stles:1,__":!..iinvil ell:4 ipalayl".1 stislips tab es Ille'alb Af .?a!•~a•.'t.$st(i1.t<l.ali w� hipal.e..•-. �r.� *rae.t l ea teal a! • , ta• a•.r a. a! .! a! a! !sob ibis sera ia!t rea err• •�I' , Se �.tf lam41,� ' �' a;a -r.+'v►�'• pTatimijioNi wed ,� .lrai� a! a! a! r! a! ai at .ii,leen 00 aver el•+tt4 - !:seas .! __ .w :;e �..:`•a Vii. r 'a►a•1a ,! • .� a! .! a•i a! a! .ii i .: P. #,: �,;�: ai%. 10+ 0 wakT,.r• .bra;. .., ai-r"....1.700. .!,al�`tl .lwasl•ae! +u" i t !tt !�►e l.'r!� la r ",iimi s � aqI f`l�a� �Berns ' 'p�ai tai�a" . 1 Flow ,Its, y, . r+ tee �.- e . �< �. �. ��S. ei,�r' a•�se ..„a�4!•ae Sa� q„ !tom ...1!•«a�'� ' 4 t; Mae. .l,�a!�a! a! a! a! a!Se So alt ,! 'i ! %AP=j killif ww 4 "'soy. it:r� Yam' Y`'v` PO �� r'� we t' . _ at .�! a 'D. OR 2 MINdiri . �teadp�P e;!jsr-7: g a • .��. _�•� . 1,r r Y Y Y. 7►► r s QQ .'� �.'!!. �r ...:!a•...�ire •s ,�� zroa.s1:+►.�.fir_ Ik • a S i wali ..... . .�a-, fl: t;.:ejt € c s _'al.!`al.al� a. a iI. -vseLT•.parr.Y� r .T �l.di.l1l., !40 41.r. It ..l a..l►�alr �►. „ea .4..►e we. +�+•., Bal a! ,c ;. a\ a! a! r_ _.�a. 5, ,, RIPRAP MORE THAN 1 . 0' ABOVE a5 ga— PIPE INVERT SHALL BE INSTALLED 6" BELOW FINISHED GRADE AND BURIED WITH TOPSOIL PLAN NTS FINISHED END TREATMENT MAY CONSIST OF RCP END SECTION GRADE (WITH TOEWALL) OR HEADWALL L II r ccT...., s..........- -,....,- ...,_,...:n i 1 TOE WALL `8" THICKNESS2D50 MItRIPRA 3 MINIMUM DEPTH P OR GEOTEXTILE EROSION VOID-FILLED RIPRAP CONTROL. MIRAFI 300 OR EQUAL PROFILE NTS WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 157 Figure 5 -5 Expansion Factor for Circular Conduits ( USDCM, Vol 2 Figure 9-35 ) 9 = Expansion Angle 8 ' - - - - 7 , f i I p m h C I c r 0 O N a d 5 , a 0 , O Cr 0 p (.) 4 by p Ls_ °` O / 4D - Z (:) - • • Q / X w / , 1 4 0, - A - - 0 . 1 .2 3 .4 . 5 .6 .7 . 8 TAILWATER DEPTH / CONDUIT HEIGHT , Y t / D WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 158 Figure 5-6 Expansion Factor for Rectangular Conduits ( USDCM , Vol 2 Fig 9-36 ) 0 = Expansion Angle 8 - 7 6 CV 5 or 4Pe g 4Q • • C • u N • h Q. • • 1/4 Q1 z � 0 3 • V 1 szt X2 1 'fir 0 0 .1 .2 . 3 . 4 .5 . 6 1 . 8 .9 1 .0 TAILWATER DEPTH / CONDUIT HEIGHT — Yt / H The size of riprap can be found using the following graph after calculating Q/ D15 and Yt/ De and reading the value from Figure 5 -7 and Figure 5 -8, shown below . Use Figure 5 - 7 to determine the required rock size for circular conduits and Figure 5 -8 for rectangular conduits . Figure 5 - 7 is valid for Q/ De' S of 6 . 0 or less and Figure 5 -8 is valid for Q/WH1 of 8 . 0 or less . The parameters n these two figures are : Q/ D1 5 or Q/WH05 in which Q is the design discharge in cfs, De is the diameter of a circular conduit in feet, and W and H are the width and height of a rectangular conduit in feet . Yt/ De or Yt/ H in which Yt is the tailwater depth in feet, De is the diameter of a circular conduit in feet, and H is the height of a rectangular conduit in feet . In cases where Yt is unknown or a hydraulic jump is suspected downstream of the outlet, use Yt/Dt = Yt/ H = 0 . 40 when using Figure 5 -7 and Figure 5 -8 . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 159 Figure 5 -7 Riprap Erosion Protection at Circular Conduit (Valid for Q/ D2 . 5≤6 .0) ( USDCM , Vol 2 Figure 9-38) 60 At 0� A'?Cr° 443 40 t4P \A O dy Oct tee tti � � pE 20 ri P E L 1 0 O . 2 .4 . 6 . 8 1 .0 Yt / D Use Do instead of D whenever flow is supercritical in the barrel . * * Use Type L for a distance of 3D downstream WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G ' 160 Figure 5 -8 Riprap Erosion Protection at Rectangular Conduit Outlet (Valid for Q/WH1 . 5≤8 .0) ( USDCM, Vol 2 Figure 9-39 ) 60 I • Iea.,to ft. ik o ��Q�� S ,d-Q, dabQt' J k. � o co ci ockQ Pr 0 _1/4 c. 4 ', A 1 L 20 , rY PE -0 . 2 .4 . 6 .8 1. 0 Yt / H Use Ha insteod of H whenever culvert hos supercritical flow in the barrel . ** Use Type L for a distance of 3H downstream After selecting the riprap size, the minimum thickness of the riprap layer is defined as : T = 2D50 Eq . 5 . 9 . 5 Table 5 - 13, below, identifies d50 based on riprap classification and gradation . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 161. Table 5-13 Classification and Gradation of Ordinary Riprap Riprap Designation % Smaller Than Intermediate Rock 43 (inches)' Given Size by Weight Dimensions (inches) Type VL 70- 100 12 50-70 9 35-50 6 6" 2- 10 2 Type L 70- 100 15 50-70 12 35-50 9 9" 2- 10 3 Type M 70- 100 21 50-70 18 35-50 12 12 " 2- 10 4 • Type H 70- 100 30 50-70 24 35-50 18 18 2- 10 6 Type VH 70- 100 42 50-70 33 35-50 24 24 2- 10 9 _ dm; = mean particle size (intermediate dimension ) by weight. " Mix VL and L riprap with 30% (by volume) topsoil and bury it with 6+ inches of topsoil, all vibration compacted, and revegetate . 5 . 10 STORAGE Weld County requires regional and/or on -site detention for all future developments . The County shall be contacted to verify if any existing drainage master plans exist in the area of work . If it is determined that there is an existing master plan for the area of work, the designer shall incorporate that information into the design and ensure that the design follows the drainage requirements set forth in the masterplan . The designer also should keep the following things in mind : • Weld County does not allow detention release rates based on soil types . • Weld County does not allow full spectrum detention to be used in sizing ponds ( see Weld County' s spreadsheets for storage capacity ) . 5 . 10 . 1 Retention Stormwater retention facilities ( stormwater infiltration facilities ) normally are not allowed in Weld County but shall be considered for special circumstances with the issuance of a variance . Variance requests shall only be considered in situations where there is a proven hardship on the proposed site . A hardship would be considered where there is not adequate topography to physically drain a pond ( sump in basin ) , refusal of an irrigation ditch to accept additional drainage, or some other physical site constraint . Variances shall be reviewed on a case - by-case basis to determine the validity of the hardship and shall be signed by the Development Review Engineer . Upon the determination that a retention ponc is applicable, the volume should be calculated as 1 . 5 x the developed site runoff for the 100-year, WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 62 24- hour storm event plus 1 foot of additional freeboard . An emergency spillway is required for retention ponds . Retention ponds may be sized using the " Modified FAA" tab on the spreadsheet referenced in the " Detention" portion of this document, using a near zero release rate per acre and extending the rainfall duration to 1440 minutes ( 24- hours x 60 minutes ) . The resulting volume at the 1440- minute interval shall be the value that must be multiplied by 1 . 5 for the final retention pond volume . A second method for calculating retention pond volume is : Volume = 1 . 5 x Area x C-Value x Rainfall • Area = Site area draining to pond ( acres ) • C-Value = Composite C-Value for area draining to pond ( based on soil type and overall , developed impervious percentage for site ) • Rainfall — NOAA Atlas rainfall depth for site location , 100-year storm at 24- hours ( in feet, divide NOAA rainfall depth in inches by 12 ) • Volume = Required Volume for Retention Pond in acre-ft The retention pond/infiltration facility shall be designed to meet Colorado Revised Statute 37-92 - 602 ( 8 ) drain time requirements . In order to meet the State Statute requirements, soil infiltration rates may be used to calculate pond drain times . However, soil infiltration rates cannot be used in the overall sizing of the detention/retention ponds . These requirements state that retention facilities : • Be solely operated for stormwater management; • Be owned and operated by a governmental entity or is subject to oversight by a governmental entity; • Continuously releases or infiltrates at least 97 percent of all runoff from a rainfall event that is less than or equal to the 5-year storm within 72 hours after the end of the event; • Continuously releases or infiltrates at least 99 percent of the runoff from a rainfall event that is greater than the 5-year storm within 120 hours after the end of the event; and • Operates passively and does not provide active water treatment processes for the stormwater. 5 . 10 . 2 Detention Developments are required to detain the runoff ( developed site condition ) produced by the 100-year, 1 - hour storm event with 1 foot of additional freeboard . Pond release rates are based off the calculated undeveloped runoff value for the site . A 2 - percent site imperviousness should be used to calculate the historic runoff rate for pond release values, regardless of site conditions prior to new site improvements . Release rates are calculated using the 5-year, 1 - hour storm for urbanizing areas and the 10-year, 1 - hour storm for non - urbanizing areas . Urbanizing areas are defined as areas within one-quarter mile of any municipal boundary, as amended . Non - urbanizing areas are greater than one-quarter mile in distance from a municipal boundary. Municipal boundaries may be found on the County' s GIS online mapping website . If the project site is within an urbanizing area or adjacent to a municipal boundary, the governing entity' s drainage criteria must be taken into consideration . Weld County requires that the WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PACE 163 more restrictive of the criteria ( if municipality is more conservative ) must be used in the drainage design of the site . The design engineer shall submit all design worksheets for pond designs in the appendices of the drainage report for review . Rainfall data/depths should be site specific and taken from the NOAA Atlas 14, online precipitation frequency data server webpage . A UD- Detention v2 . 34 worksheet is available on the Weld County Planning and Zoning Development Review webpage . This spreadsheet is an older, archived version of the MHFD' s spreadsheet, which utilizes the " Modified FAA" procedure for pond sizing with the County approved C-values . The County DOES NOT accept the full spectrum detention pond design method . The design consultant may use the downloadable spreadsheets or may create their own based on the information provided in this document . If created spreadsheets are utilized , they must comply with the design requirements in this document . Rainfall duration times should be extended until the pond reaches a peak volume, after which the pond volume falls . If the peak is not reached within a reasonable time period ( less than two to three hours ± ) the volume at the 60- minute interval may be taken as the required detention volume for the site . If a series of detention ponds are proposed on -site, the County may require a SWMM model be created for the development, so that the pond volumes/water surface elevations can be analyzed as routed ponds . An excerpt from a previous version of USDCM , Volume 2 on the Modified FAA procedure has been provided on the Weld County Planning and Zoning Development Review Webpage, and in Appendix F for reference, if the consultant would like to create their own pond -sizing spreadsheet . The outlet works for detention and water quality facilities shall be designed to meet Colorado Revised Statute 37 -92 -602 ( 8 ) , drain time requirements . In order to meet the State Statute requirements, soil infiltration rates may be used to calculate pond drain times . However, soil infiltration rates cannot be used in the overall sizing of the detention/retention ponds . These requirements state that detention facilities : • Be solely operated for stormwater management; • Be owned and operated by a governmental entity or be subject to oversight by a governmental entity; • Continuously release or infiltrate at least 97 percent of all runoff from a rainfall event that is less than or equal to the 5-year storm within 72 hours after the end of the event; • Continuously release or infiltrate at least 99 percent of the runoff from a rainfall event that is greater than the 5 -year storm within 120 hours after the end of the event; and • Operate passively and do not provide active water treatment processes for the stormwater . 5 . 10 . 2 . 1 Pond Layout Considerations The geometry of a stormwater detention facility depends on specific site conditions such as adjoining land uses, topography, geology, preserving or creating wildlife habitat, and volume requirements . Several key features must be incorporated in all detention facilities : • Embankments and side slopes shall have a maximum slope of four feet horizontal to one foot vertical (4 : 1 ) and shall be stabilized . Slopes steeper than 4 : 1 in detention basin areas will not be accepted . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 164 • Detention basin embankments shall be designed to withstand the 100-year and larger storm . Poorly compacted native soils shall be excavated and replaced . Embankment soils shall be compacted to at least 95 percent maximum density ( Modified Proctor) or as specified in the geotechnical report for the site . • Detention basin bottoms shall have a minimum slope of 1 percent for vegetated surfaces . If the desired slope is not attainable, a bottom slope of 0 . 5 percent may be used with a concrete trickle channel . • Water quality and detention flows are released through an outlet structure . The minimum outlet pipe size for use in detention facilities is 12 - inch diameter ( or equivalent ) . Orifice/restrictor plates may be used to reduce flows from the minimum pipe sizes . • When possible, place inflow culverts as far from the pond outlet as possible for increased water quality through pond vegetation . • Inflow points shall enter the detention basin at or near the toe of the basin to prevent erosion along the basin embankments . If providing an inflow point at the toe of the basin is not feasible, then erosion protection must be provided from the inflow all the way to the toe of the basin . • Detention basin bottom must be a minimum of 24 inches above the groundwater elevation . ( Groundwater elevation data must be determined during high groundwater months . ) • Detention basins must be located a minimum of 20 feet away from an irrigation ditch or other facility, or more if specified by the owner of the irrigation canal and protected from seepage from the irrigation canal . • Stormwater infiltration facilities shall not be placed in the FEMA mapped floodway and should not be placed in the FEMA mapped 100-year floodplain . Any berming within the floodplain will require a floodplain study, which may result in the need for a LOMR/CLOMR . 5 . 10 . 2 .2 Water Quality With drain time requirements in mind , the outlet works for an extended detention basin shall be designed to release the water quality capture volume ( WQCV) over a 40- hour period . The WQCV may be calculated , along with the orifice hole sized , on the MHFD spreadsheet . An alternate method to calculate the required WQCV is to use the equations taken from USDCM , Volume 3 as shown below . The WQCV is calculated as a function of imperviousness and BMP drain time using Eq . 5 . 10 . 2 . 1 , and as shown in Figure 5 -9 : WQCV = a ( 0 . 91i3 — 1 . 1912 -I- 0 . 78i ) Eq . 5 . 10 . 2 . 1 Where : WQCV = Water Quality Capture Volume (watershed inches ) a = Coefficient corresponding to WQCV drain time ( 5- ) i = Imperviousness ( %/ 100) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 165 Figure 5-9 Water Quality Capture Volume (WQCV) Based on BMP Drain Time ( USDCM , Vol 3 Fig 3-1 ) 0, 500 ,. _ - 14O hour drain time 0, 450 .- oee 4) 0, -'0MJr at [ 24 hour drain tune i ee C ©. 350 1 , - - ---- -- -- - - --- -- - - - - - - ---e Mr -V a(1. 91901 , 1912+0. 781) i� • 0. 300 - I $ -I- de ./ n 12-hrdraintime a = 0. 8 , 0 a. U 24 -hr drain time a : 0. 9 - _ 41/0 40-hr drain time a = 1 . 0 se "' ` 400 0. 2`00 tireo es sOF 1 0. 150 a i fo 0 ,� 12 hour drain tw e I a 0. 140 i ".' 0. 050 - . } 0. 000 - • 0 0, 1 0, 2 0 . 3 u 4 0 5 0 6 0. 7 0. 8 0.9 1 Total Imperviousness Ratio ( i = la/100) Figure 3- 1 . Water Quality Capture Volume MVO( } Based on [IMP Drain Time Table 5-14 Drain Time Coefficients for WQCV Calculations Drain Time ( hrs) Coefficient, a 12 hours 0 . 8 24 hours 0 . 9 40 hours 1 . 0 Weld County does not require the use of trash racks be placed in front of the water quality plate . It shall be at the discretion of the design engineer if trash racks are included . The WQCV is considered a part of the overall detention/ retention volume requirement and should not be added to the volume . The water quality orifice plate perforations also may be found using the chart in Table 5- 15 only . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 166 Table 5- 15 WQCV Outlets Orifice Plate Perforation Sizing Orifice Plate Perforation Sizing Circular Perforation Sizing This table may be used to size perforation in a vertical plate of riser pipe . Hole Dia . Hole Dia . Min . S. Area per Row ( sq . in . ) (in . ) * (in . ) i; in . ) n = 1 n = 2 n = 3 1 /4 i 0 . 250 1 0 . 05 4 0 . 10 0 . 15 , 5/16 0 . 313 2 0 . 08 0. 16 0 . 24 3/8 0 . 375 2 0 . 11 0. 22 0 . 33 7/16 0 . 438 2 0 . 15 0 . 30 0 . 45 1 /2 0 . 500 I 2 0 . 20 0. 40 0 . 60 9/16 I 0 . 563 3 0 . 25 0 . 50 I 0 . 75 5/8 0 . 625 3 0 . 31 0 . 62 0 . 93 11 /16 0. 688 3 0 . 37 i 0 . 74 1 . 11 3/4 0 . 750 3 0 . 44 0 . 88 1 . 32 13/16 0 . 813 3 0 . 52 1 . 04 1 . 56 7/8 0. 875 3 0 . 60 1 .20 1 .80 15/16 0 . 938 3 0 . 69 1 . 38 2 . 07 1 1 . 000 4 0 . 79 1 . 58 2 . 37 1 1 /16 1 . 063 4 0 . 89 I 1 . 78 2 .67 1 1 /8 1 . 125 4 0 . 99 1 .98 2 . 97 1 3/16 1 . 188 4 1 . 11 2. 22 3 . 33 1 1 /4 1 . 250 4 1 . 23 2 . 46 3 . 69 1 5/16 1 . 313 4 1 . 35 2 . 70 4 . 05 1 3/8 1 . 375 4 1 . 48 2. 96 4 . 44 1 7/16 1 . 438 4 1 . 62 3. 24 4 . 86 1 1 /2 1 . 500 4 1 . 77 3 . 54 I 5 . 31 1 9/16 1 . 563 4 1 .92 3 . 84 5 . 76 1 5/8 1 . 625 g 4 2 . 07 4 . 14 6 . 21 1 11 /16 1 . 688 4 2 . 24 4. 48 6 . 72 1 3/4 1 . 750 4 2 . 41 4 . 82 7 . 23 1 13/16 1 . 813 4 2 . 58 5 . 16 7 . 74 1 7/8 1 . 875 4 2 . 76 5 . 52 8 . 28 1 15/16 1 . 938 4 2 . 95 5. 90 8 . 85 2 I 2 . 000 l 4 7 3 . 14 1 6 . 28 _ 9 . 42 n = Number of columns of perforations Minimum steel plate thickness 1 /4 " 5/16" 3/8 " * Designer may interfere to the nearest 32 ' "j inch to better match the needed area if desired. Rectangular Perforation sizing Rectangular Min . Steel Use only one rectangular column whenever two hole Width Thickness 2 ; inch diameter circular perforations cannot provide 5" 1 /4 " needed outlet area . 6" 1 /4 " 7" 5/32 " Rectangular Height = 2 - inches 8" 5/16 9" 11 /32 " 10" 3/8 " Rectangular Width = Required Area per Row / 2 " > 10'' 1 /2 ., WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A (T F 167 5 . 10 . 2 .3 Outlet Structure Included below is a typical configuration for a detention pond outlet structure . The detail shows the general features and layout of the basic components of a typical outlet structure . Figure 5 - 10 is not a construction detail . The design engineer will be required to design the outlet structure to meet the needs of the individual site plan and topography . In addition , the following items must be included in the outlet structure design : • The outlet pipe must contain a minimum of two concrete cutoff walls embedded a minimum of 18 inches into undisturbed earthen soil . The cutoff walls must be a minimum of 8 inches thick . • The outlet pipe bedding material must consist of native earthen soil , not granular bedding to at least the first downstream manhole or daylight point . • A water quality plate designed to release the WQCV in 40- hours attached to the front of the structure . Plate should be a tight fit with no gaps . Gasket or seal could help facilitate this fit . • A restrictor plate attached to the back wall of the structure to limit the pond release to the calculated 5 -year or 10-year historic runoff rate for the site ( see detention pond section for details ) . • The outlet pipe must be a minimum diameter of 12 - inches . • To reduce maintenance and avoid operational problems, outlet structures must be designed with no moving parts other than the trash rack ( i . e . use only pipes, orifices, and weirs ) . Manually and/or electrically operated gates shall be avoided . To reduce maintenance, outlets should be designed with openings as large as possible, compatible with the depth -discharge relationships desired and with water quality, safety, and aesthetic objectives in mind . • Outlets should be robustly designed to lessen the chances of damage from debris or vandalism . Avoid the use of thin steel plates as sharp-crested weirs to help prevent potential accidents, especially with children . Trash racks must be provided on all outlet structures . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G F 68 Figure 5-10 Outlet Structure Plan and Profile Example OUTLET REQUIREMENTS OUTLET STRUCTURE - WQCV SHALL BE RELEASED OVER 40 HOURS r OUTLET PIPE - OUTLET WORKS SHOULD BE SIZED AND 12" MIN STRUCTURALLY DESIGNED TO RELEASE AT NO MORE THAN THE 1 -HOUR, 5-YEAR HISTORIC RELEASE RATE IN URBANIZING b3 "11- — RESTRICT0R AREAS AND THE 1 -HOUR. 10-YEAR HISTORIC i� ORIFICE PLATE RELEASE RATE IN NON-URBANIZING AREAS. aises - OPENINGS IN THE SAFETY GRATE SHALL - - -- --1 - - ALLOW ENOUGH FLOW TO PASS THE 5-YEAR OR 10-YEAR HISTORIC FLOW (DEPENDENT ON URBANIZATION CLASSIFICATION). USING SAFETY - A 50% CLOGGING FACTOR. GRATE N., NA. WATER QUALITY - STEEL FOR GRATES AND GRATE / PLATE INSTALLATION HARDWARE SHALL BE GALVANIZED AND CONSTRUCTED IN A A' ACCORDANCE WITH COOT SECTION 712.06. + 4 I , - CONCRETE SHALL BE CDOT CLASS D, 4500 PSI IN 28 DAYS, PER COOT SPECIFICATION CO aill— SECTION 601 . PLAN VIEW - REINFORCEMENT BARS SHALL BE PER COOT WQCV WSEL SPECIFICATIONS. SPACING AND SIZE TO BE / DETERMINED BY CONSULTING DESIGN / ENGINEER, - --- L,...--------___----"----__----" � I - I - STEPS SHALL BE PROVIDED WHEN HEIGHT IS , I I 100-YEAR RESTRICTOR GREATER THAN 3'-6" AND SHALL CONFORM I I ORIFICE PLATE PLATE V TO AASHTO M 199. S' i I + (3/8" MIN HOT-DIPPED I I a GALVANIZED) WQCV ORIFICE PLATE (HOT-DIPPED 1 I OUTLET PIPE GALVANIZED STEEL) -O- - 1 `r IA 12' MIN. I r I 1 - I , j • 4 v II f f E F 1 I r 1 II ' - I ni 1 ( I I _ + € I I I '_' SECTION A-A' SAFETY GRATE WQCV WSEL 1 / i 1 1O0-YEAR RESTRICTOR • ORIFICE PLATE PLATE (3/8' MIN. HOT-DIPPED 4 GALVANIZED) WQCV ORIFICE PLATE HOT-DIPPED OUTLET PIPE GALVANIZED STEEL \,� I 12' MIN. \z / \\Y . - , IVI1/4/7\7 \// \V / /` \/ \/ \/- \/ N: N:// / /\ \ /X •/\ /'/, / . / >,\//\/\// , /\ / SECTION B-B' 5 . 10 . 2 .4 Stage Storage Curves A relationship between the water surface elevation and detention basin volume, commonly referred to as a "stage-storage" curve, needs to be developed for each pond . The afore mentioned MHFD spreadsheet will calculate a stage -storage table based on overall pond dimensions, however the County WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 169 requires the stage-storage volumes be based on the actual site design contours . The volumes may be calculated in the " Basin" tab of the spreadsheet by using the " Surface Area at Stage ( ft2 ) override" column or by using the equation below . Another method of calculating the stage -storage volume is called the "Conic" method and is based on the following formula : V = D A B E 5. 10. 2 . 2 VAR ) q. Where : V= Volume between two contours, ft3 D = Depth between contours, feet A = Area of bottom contour, ft2 B = Area of top contour, ft2 A cumulative volume should be provided for the progressing stages/depth of the pond . The required pond volume for water quality and detention should be compared to the available pond volume provided in the design . The information should be clearly shown in the project' s drainage report . 5 . 10 . 2 . 5 Spillway Detention ponds and stormwater infiltration facilities ( retention ponds ) shall contain an emergency spillway capable of conveying the peak 100-year storm discharge ( from developed site ) draining into the pond/infiltration facility . The spillway also should be capable of passing any off-site flows that are routed through the pond un -detained . The spillway location should be placed so that downstream properties or residences are not adversely affected . The invert of the emergency spillway must be equal to or above the 100-year WSEL. The elevation of the top of the embankment should be a minimum of 1 foot above the water surface elevation when the emergency spillway is conveying the maximum design or emergency flow . The depth of flow over the emergency spillway shall be 6 inches or less . Additional spillway details are shown in Appendix J . Flow over a horizontal spillway can be calculated using the following equation for a horizontal broad - crested weir, shown below . Q = CBCW LH1 . 5 Eq . 5 . 10 . 2 . 3 Where : Q = Discharge, cfs CBcw = Broad -crested weir coefficient, dimensionless ( ranges from 2 . 6 to 3 . 0 ) L = Length of weir, ft H = Head above weir crest, ft In addition, the County requires the following items be included in the spillway design . • A concrete cutoff wall 8 inches thick, 3 feet deep, and extending a minimum of 5 feet into the embankment on each side of the emergency spillway opening is required on all privately maintained detention ponds/infiltration facilities and regional detention ponds/infiltration WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 170 facilities . The concrete cutoff wall permanently defines the emergency spillway opening . The emergency spillway elevation shall be tied back into the top of the embankment using a maximum slope of 4 : 1 . • To protect the emergency spillway from catastrophic erosion failure , riprap shall be placed from the emergency spillway downhill to the embankment toe of slope , with a toe - down constructed to a depth of 4xD50 . The minimum D50 for riprap on the emergency spillway shall be 12 inches (Type M ) . Riprap may be either grouted or buried . If buried , the protected area shall be covered with 6 inches of topsoil and seeded . Revegetation requirements for storage facilities can be found in Chapter 8 of this WCECC . A detail of the preferred spillway design is in Figure 5 - 11 below . Figure 5 -11 Emergency Spillway Typical Design EMERGENCY SPILLWAY r 100 YEAR WSEL - 1' MINIMUM OR HIGHER - V MINIMUM 6" MAXIMUM FLOW OVER WIAXIMUM SLOPE OF 4'1 5, SPILLWAY �- -� la-- 5' -4-1VARIES 1 t w - r - 7N 1 .1 4.1.-44.1 S —.:...i. ::-.4.:i ✓_-.p' =4 i.. - a -a. TWO li5 BARS 1a:j,.YW' h O' i FRONT VIEW OVERTOPPING SPILLWAY WATER SURFACE 100 YEAR WSEL I 6. MAX-+{ 1 8" MINIMUM THICKNESS 1 F - _.,r• , • , L COMPACTED EARTH 95% STANDARD 3 ' r-� PROCTOR DENSITY SAFETY GRATE - \ ti � � BURIED OR GROUTED RIPRAP (DEPTH = 2 x D,,, ) WQCV WSEL EMERGENCY -J �'� ••� PLACED TO TOE OF SLOPE SPILLWAY WALL O`��` �'~•� 100-YEAR � GEOTEXTILE FABRIC MIRAFI FIN 300 WQCV RESTRICTOR �.r' OR APPROVED EQUAL PLATE ORIFICE 14 ti~ �'•�' PLATE I I I /\ , • LOW TAILWATER BASIN i I IF VELOCITY EXCEEDS 2 FPS d. �,`�•� I / II / ,4►�� ' �11 ��' �`�►, ...: r CONCRETE OUTLET PIPE CUTOFF WALL MINIMUM SIZE 12- HEADWALL AT CONCRETE END OF PIPE CUTOFF WALL EMERGENCY SPILLWAY REQUIREMENTS SIDE VIEW - EACH DETENTION POND SHALL CONTAIN AN EMERGENCY SPILLWAY CAPABLE OF CONVEYING THE PEAK 100-YEAR STORM AT A DEPTH OF SIX (6) INCHES OR LESS BURIED OR GROUTED RIPRAP SHALL BE PLACED FORM THE EMERGENCY SPILLWAY DOWNHILL TO THE EMBANKMENT TOE OF SLOPE AND COVERED WITH SIX (6) INCHES OF TOPSOIL. IF BURIED THE RIPRAP MUST BE SIZED AT THE TIME OF FINAL ENGINEERING DESIGN GROUTING OF THE RIPRAP MAY BE REQUIRED - IN ORDER TO PREVENT DAMAGE TO PUBLICLY-OWNED INFRASTRUCTURE (ROADS, ROADSIDE DITCHES), A CONCRETE CUTOFF WALL EIGHT (8) INCHES THICK. THREE (3) FEET DEEP AND EXTENDING A MINIMUM OF FIVE (5) FEET INTO THE EMBANKMENT ON EACH SIDE OF THE SPILLWAY OPENING IS REQUIRED ON ALL DETENTION PONDS THE EMERGENCY SPILLWAY ELEVATION MUST BE TIED BACK INTO THE TOP OF THE EMBANKMENT USING A MAXIMUM SLOPE OF 4. 1 CONCRETE SHALL BE CDOT CLASS D. 4500 PSI IN 28 DAYS. PER CDOT SPECIFICATION SECTION 601 . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 171 5 . 10 . 2 .6 Maintenance Maintenance for stormwater storage facilities should follow the recommendations in the USDCM , Volume 3, unless otherwise specified by the design engineer. It is recommended that stormwater infiltration facilities be scraped/plowed every few years to prevent sedimentation and/or clogging and to ensure proper infiltration is being achieved . Areas designated for stormwater drainage , detention, or stormwater infiltration , are not to be used for materials storage, building, or parking, and should not be modified without approval from the Department of Public Works . Access also must be provided to the drainage facilities for long-term maintenance . Refer to Section 5 . 3 . 1 of this WCECC for O & M submittal requirements . 5 . 10 . 2 . 7 Exceptions to Detention Requirements Exceptions to stormwater detention shall not jeopardize the public health , safety, and welfare of public and private property . The following exceptions are provided in Chapter 8, Article XI , of the Weld County Code and are subject to updates : • Use by right or accessory use in the A (Agricultural ) Zone District • Zoning permits for accessory storage, commercial vehicles, home occupations, or manufactured homes in the A ( Agricultural ) Zone District • A second dwelling permit in the A (Agricultural ) Zone District • Towers, including but not limited to wind and telecommunication towers • Pipelines or transmission lines, excluding laydown yards, metering sites, substations, and any other above ground appurtenances • Gravel pits, if the stormwater drains into the gravel pit . Releases from the site shall comply with this Engineering and Construction Criteria Manual , including dewatering . Topographical information will be provided . • Rural residential developments with no historic flooding, where all the following conditions exist . This exception shall be supported by calculations provided by the Applicant . Additional information may be requested and will be signed and stamped by a Colorado licensed Professional Engineer: a . Nine ( 9 ) lots or fewer . b . The minimum lot size is equal to , or greater than, three ( 3 ) acres per lot . c . The total post-development imperviousness for the rural residential development does not exceed ten percent ( 10% ) , assuming that all internal roads and driveways are paved . • Development of sites where the change of use does not increase the imperviousness of the site . Note : This exception cannot be applied to sites where impervious surfaces were added for, or in conjunction with , a business that is/was operating in violation and/or without the required Weld County land use permit . • A parcel of land or project site where the "total developed stormwater runoff" from the 100- year, 1- hour storm is less than , or equal to, five ( 5 ) cfs . The "total developed stormwater runoff" includes cumulative runoff from the proposed project site plus runoff from any previously developed project site on the subject parcel . A project site is the area of land that lies within the project' s limits of disturbance during construction . This exception shall be supported by calculations signed and stamped by a Colorado Licensed Professional Engineer . • In -fill development parcels with total area less than , or equal to, one ( 1 . 0 ) gross acre . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 172 • An individual parcel with an unobstructed flow path and no other parcel ( s ) between the channel within a Federal Emergency Management Administration ( FEMA ) regulatory floodplain and the project . • A parcel greater than one ( 1 ) gross acre and less than , or equal to five ( 5 ) gross acres in size is allowed a onetime exception for a new four thousand ( 4, 000 ) sq . ft . building or equivalent imperviousness . • A parcel > 5 gross acres in size is allowed a onetime exception for a new 4, 500 sq . ft . of 100% impervious area or equivalent imperviousness . • A parcel greater than five ( 5 ) gross acres in size is allowed a onetime exception for a new nine thousand ( 9, 000 ) sq . ft . of 100 % imperviousness area or equivalent imperviousness . • Concentrated Animal Feeding Operations ( CAFOs ) , Animal Feeding Operations ( AFOs ) , and Housed Commercial Swine Feeding Operations ( HCSFOs ) which are covered and approved by the Colorado Discharge Permit System ( CDPS ) regulations . Portions of the site not included or covered by the CDPS permit shall comply with the criteria set forth in this Chapter . Exception requests shall be supported with an approved drainage narrative, which must describe the following minimum criteria : • The exception being requested for consideration . • Any existing and proposed improvements to the property . • Where the water originates if it flows onto the property from an offsite source . • Where the water flows as it leaves the property . • The direction of flow across the property . • Previous drainage problems with the property, if any . • The location of any irrigation facilities adjacent to or near the property . • Any additional information pertinent to the development . During the review of the application , the Weld County Department of Planning and Zoning will determine if the exception is applicable and will not jeopardize the health , safety, and welfare of public and private property . 5 . 10 . 3 Darn Information All detention ponds shall be evaluated to verify if the detention facility would be classified as a non - jurisdictional or jurisdictional dam , per the State of Colorado Department of Natural Resources criteria . Refer to Table 5 - 16 . Table 5-16 Non-Jurisdictional vs Jurisdictional Dam Criteria Summary Non-Jurisdictional Dam Jurisdictional Dam Jurisdictional Height of Berm < 10 ft > 10 ft Water Storage Area ( at High Water < 20 ac > 20 ac Line ) Water Storage Volume < 100 ac-ft > 100 ac-ft *This table is a general summary of the required State Criteria. The Designer shall be required to determine which category their design would be classified as and determine the required protocol. This information will then be supplied to the County for record keeping purposes. WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA 173 If it is determined that the detention facility is classified as a jurisdictional dam , state procedures must be fcllowed . It should be noted that non -jurisdictional - size dams are regulated and subject to the authority of the State Engineer consistent with Sections 37 -87-012 and 37-87- 105 C . R . S . , Implementation of detention ponds, and will require the design engineer to consult with the State Engineer' s Office to verify the legal right to store water . 5 . 10 .4 Irrigation Ditches/ Private Irrigation Systems It is not the intent to allow new private irrigation systems to be located within County right- of-way . Irrigation ditches shall not be used as conveyance systems and /or outfall points for stormwater runoff for all land use cases including, but not limited to : Uses by Special Review, Site Plan Reviews, Subdivisions, or Planned Unit Developments, unless such use is approved , in writing, by the ditch owner( s ) . The approval shall be in the form of signature on the construction plans/documents or other formal legal agreements as required by the ditch company or owner . Should direct discharge of stormwater runoff be permitted , water quality treatment may still be required . In the instance where an irrigation ditch serves as the outfall for a stormwater detention facility, the following items must be met : • The maximum water surface elevation must be determined based on the maximum amount of irrigation flow in the ditch . The appropriate owner/ditch or reservoir company is the determining authority regarding the maximum irrigation flow in the ditch . Written verification of the maximum irrigation flow from the owner/ditch or reservoir company must be submitted with the hydraulic analysis of the ditch water surface elevation . • The detention outlet must be designed such that backflow from the ditch into the detention facility is prevented . • The backwater effects caused by the design of a detention outlet, if any, must be reviewed and approved by both the County and the appropriate ditch or reservoir company . • The outlet design must consider tailwater effects on the outlet pipe resulting from the combination of the maximum irrigation flow and the 100-year storm discharge within the ditch . • Drain times need to adhere to Colorado Revised Statute 37 -92 - 602 ( 8 ) drain time requirements as listed in the " Detention Pond " section of this document . If new developments are adjacent to irrigation facilities but no flows are being directed into the ditch , the owner/ ditch or reservoir company must still be notified of the proposed development . In such cases, it shall be the developer' s engineer responsibility to provide drawings and calculations to support the fact the irrigation ditch is not impacted . These drawings and calculation shall be supplied to the County and ditch company owner . The party seeking modifications to existing ditch conditions must obtain the appropriate owner / ditch or reservoir company approvals and signatures prior to seeking Weld County approval for such modifications . The party seeking modifications to the existing irrigation facilities must coordinate with the irrigation system owner/operator to provide an adequate design to make the irrigation system function as it did prior to the improvements . When modifications to existing irrigation systems are necessary, the following must be provided to the County review staff: WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G T. 174 • Information on how the existing private irrigation facilities are to be protected or routed through the project site . • Plan and profile drawings of any new irrigation pipes should be included in the drawing set, similar to information for proposed storm lines . • A hydraulic model showing the irrigation pipe system at full irrigation flows should be provided in the drainage report for review by County staff. • Irrigation flows should be provided by the owner of the irrigation system , not estimated on existing pipe or ditch sizes . • Details of any irrigation structures required should be provided in the plan set for the development . Dimensions of the structures, concrete type and thickness, rebar type and spacing, grates, weir boards, bridge, trash racks, connecting hardware, air vents etc . should be included in the details of the irrigation structures . • Owner approval of the new system is required before construction can proceed . • Proposed private irrigation facilities for new developments or reconfigured existing irrigation systems should be located outside of the public right-of-way . As- built survey is required documenting all changes in direction and structure critical elements plus video of all pipes installed verifying pipe connections and debris removal . 5 . 11 STORMWATER DRAINAGE CRITERIA VARIANCES In cases of hardship, an applicantmay apply for a variance from a requirement of the storm drainage criteria . Weld County will not approve design variances found to be detrimental to the public health , safety, and general welfare or when the request is contrary to the purpose and intent of the criteria set forth in this document or the Weld County Code . The variance procedure is intended to address cases of hardship, and requests will not be granted when the hardship is brought about solely through the actions of the appellant . Variance requests shall be stamped and signed by a professional civil engineer licensed to practice in the State of Colorado and shall be submitted with the Certificate of Compliance . Variance requests will be reviewed by the Development Review Engineer. To be reviewed , the variance request must : • State the hardship that is causing the request for a variance from Weld County Code . Provide proof of the hardship in the drainage memo/letter provided . • Describe the design criteria of the Weld County Code from which a variance is being requested . • Describe the proposed alternative with engineering rationale that supports the intent of the Weld County Code . • Meet the design intent of the Weld County Code . • Demonstrate that granting of the variance will still adequately protect public health , safety, and general welfare . • Demonstrate there are no adverse impacts from stormwater runoff to the public rights of way and/or offsite properties as a result of the project . Applicants may appeal the denial of a variance to the BOCC pursuant to the provisions in Chapter 2, Article IV, Section 2 -4- 10 of the Weld County Code . Variance requests, if accepted , are not precedent setting and are based on site-specific constraints . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PACTF 175 5 . 12 OIL AND GAS STORMWATER MANAGEMENT The following standards apply only to the development of oil and gas exploration and production in the Weld Mineral Resource ( Oil and Gas ) Area . These standards shall be supported by calculations signed and stamped by a Colorado licensed Professional Engineer and accepted by the Weld County Department of Public Works . See also Chapter 21 of the Weld County Code . • Oil and Gas Tank battery secondary containment . When calculating the Oil and Gas Location imperviousness and pervious areas, secondary containment areas may be excluded from the total site imperviousness and pervious calculations provided that the secondary containment area is appropriately sized to hold the originally designed safety containment volumes plus the 100-year, 1- hour storm rainfall event . • Detention pond storage volume . In non - urbanizing areas during the Construction Phase, detention ponds shall be sized to store the stormwater runoff generated by the 1- hour, 100- year storm falling on the developed site and release of the detained water at the historic runoff rate of the 1 - hour, 10- year storm falling on the undeveloped site or at 5 cfs, whichever is greater. Historic is defined as an undeveloped site ( before any development ) with an assumed 2 . 0 percent imperviousness maximum . During the Production Phase or in urbanizing areas, detention ponds shall adhere to Sec . 8- 11 - 100 . A. 1 . of the Weld County Code . • Detention pond freeboard . During the Construction Phase, less than 1 foot of freeboard may be allowed on a case - by-case basis . This exception shall be supported by calculations signed and stamped by a Colorado licensed Professional Engineer and accepted by the Weld County Department of Public Works . During the Production Phase, the detention pond shall adhere to Sec . 8- 11 - 100 .A .4 of the Weld County Code . • Emergency spillway . To prevent damage to publicly owned infrastructure ( roads, roadside ditches ) , a cutoff wall is required on all privately maintained detention ponds and retention ponds . The cutoff wall permanently defines the emergency spillway opening . The emergency spillway elevation must be tied back into the top of the embankment using a maximum slope of 4 : 1 . The cutoff wall must either be constructed of concrete or galvanized steel sheet pile . Concrete cutoff walls must adhere to Sec . 8- 11 - 100 . A . 7 of the Weld County Code . Steel sheet pile cutoff walls must be hot dipped galvanized steel of %- inch thickness or 3 -gauge and extend 3 feet below the bottom of the pond or per manufacturer' s recommendation , whichever is greater. If steel sheet pile is proposed for the cutoff wall, the native soils must be tested for sulfate levels . If the sulfate levels are above 1 . 0 percent, the sheet pile shall be coated with a corrosion - resistant epoxy . • Retention pond . Retention facilities shall be allowed without a variance only during the Construction Phase . Retention facilities that are proposed for the Production Phase require the issuance of a variance requested by the Applicant and accepted by the Weld County Department of Public Works . Additionally, as part of the application for a 1041 WOGLA Permit, an Operator shall provide proof of a valid stormwater discharge permit issued by CDPHE . The Operator shall submit a drainage report to comply with required Storm Drainage Criteria pursuant to Chapter 8, Article XI of the Weld County Code . Additional requirements for Municipal Separate Storm Sewer System ( MS4 ) areas may be applicable pursuant to Chapter 8, Article IX of the Weld County code . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 176 CHAPTER 6 GRADING AND MS4 REQUIREMENTS 6 . 1 EROSION CONTROL & GRADING REQUIREMENTS Weld County requires an erosion control and grading plan . Erosion control methods are implemented to prevent the offsite transport of sediment from land - disturbing activities . Erosion has the potential to damage adjacent properties and County drainage systems, as well as contributing to the degradation of water quality . When properly installed and maintained , temporary control measures provide effective erosion control for a site . At a minimum , a stormwater management plan ( SWMP ) shall include erosion control and grading plans . 6 . 1 . 1 Applicability Sites disturbing more than one acre ( Sec . 8- 12 -30 . B ) of land disturbance require a Grading Permit . For MS4 areas a grading permit may be required for any disturbance . The definition of disturbance in the Weld County Code is when the surface area is disturbed by any work activity upon the property by means including, but not limited to, grading; excavating; stockpiling soil , fill , or other materials; clearing; vegetation removal ; removal or deposit of any rock, soil , or other materials; or other activities that expose soil . Disturbed area does not include the tillage of land that is zoned agricultural or the tillage of a parcel zoned PUD ( planned unit development ) within the area identified for agricultural uses . For Grading Permit exemptions, refer to Section 8- 12 - 30 of the Weld County Code . 6 . 1 . 2 Grading and Erosion Control Plans When applying for a Grading Permit, a Grading Plan , a Utility Map ( Sec . 8- 12 -50 . C ) , a Drainage Plan and a Sediment & Erosion Control Plan shall be submitted for review . A Grading Permit Checklist, provided in Appendix G , should be used for guidance in developing the Grading Plan and Sediment & Erosion Control Plan to expedite the review process . The main components of the Grading Plan and Sediment & Erosion Control Plan are : 1 . Site Drainage — identifying existing and proposed grading and drainage features ( swales, inlets, manholes, curb and gutter, concrete pans, culverts, roof drains, ponds, and outlet structures ) designed to convey stormwater runoff. Site grading will be consistent with accepted Drainage Plan for the site . 2 . Temporary Control Measures ` BMPs ) — identifying, detailing, and locating all structural and non - structural temporary control measures used during each phase of construction , from initial disturbance to final stabilization , to prevent the discharge of sediment from the site . Additionally, the plan will include installation , implementation , maintenance, and removal specifications for each structural control measure and a narrative description of each non - structural control measure . 3 . Permanent Stabilization — identifying the means and methods used to achieve stabilization for all disturbed areas . Stabilization includes, but is not limited to; seed mix, seed application method , mulch type, mulch application method , soil testing, soil amendments, and erosion control blankets . Additionally, the plan will include installation , implementation , and maintenance specifications for each structural control measure and a narrative description of each non -structural control measure . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 178 A complete set of plans will include separate plan sheets for all three phases of construction identified as follows : 1 . Initial Phase — depicting current site conditions, including existing structures, drainage patterns, topography, etc . 2 . Interim Phase — depicting temporary control measures used during active construction . Depending on construction phasing, multiple sheets may be required . At a minimum , vehicle tracking, perimeter control and inlet/outlet protection will be addressed with temporary control measures . In addition , the plans should note that a state - issued Dewatering Permit will be obtained and submitted to Weld County prior to any dewatering activities . 3 . Final Phase — depicting temporary control measures to remain in place after construction until the site reaches final stabilization . Final stabilization is when all landscaping is complete and seeding has reached at least 70 percent permanent vegetative cover . At a minimum , perimeter control will remain in place and maintained until final stabilization is reached . In addition , other temporary control measures may be required to remain in place and maintained , if necessary, to prevent offsite sediment transport while waiting for vegetative growth . Plan sheets will be submitted electronically and should be clear and legible . The Development Review Engineer reserves the right to require plan modifications for readability purposes . In addition , each temporary control measure used will be located on the applicable site plan and referenced in the legend , and an installation and implementation specification will be attached . Public Works recommends using USDCM Volume 3 , Chapter 7, Construction BMPs, for clear and specific installation and implementation specifications . Other methods may be approved on a case - by-case basis . 6 . 1 . 3 Implementation During construction , the Grading Plan , Utility Map, Drainage Plan and Sediment & Erosion Control Plan shall be kept onsite and available for reference by site workers and County inspectors . In accordance with the state - issued Construction Permit, temporary control measures should be inspected by a Qualified Stormwater Manager at a minimum of every two weeks and after storm runoff events; however, more frequent inspections may be necessary to properly maintain temporary control measures . If changes to the approved Grading Plan and Erosion & Sediment Control Plan are necessary, Weld County shall be contacted to determine if a Grading Permit modification is necessary . Weld County inspectors shall verify site conditions with the approved set of plans . Violations may occur if site conditions do not reflect the approved plans . 6. 1 .4 Grading Permit Deadline (Fee) & Extension 6. 1 . 5 Tracking Control Tracking control is required when construction activity is accessing onto a roadway surface other than gravel . There are three tracking control options when required to mitigate impacts to the public road , including damages and/or offsite tracking of mud or other materials . Regardless of option , drainage and/or culverts must be maintained . The associated appropriate tracking control devices for each situation are listed below . • Permanent access onto concrete , asphalt, or recycled asphalt ( RAP ) public road WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 179 a . Double cattle guards used in combination with 100 feet of asphalt b . Or 300 feet of asphalt • Permanent access onto gravel public road a . Double cattle guards with 100 feet of aggregate surface course ( See Section 9 . 6 . 6 ) b . Or 300 feet of aggregate surface course ( See Section 9 . 6 . 6 ) c . Aggregate surface course ( See Section 9 . 6 . 6 ) on all drive surfaces • Temporary access onto either concrete, asphalt, or recycled asphalt ( RAP ) or gravel public road . Culverts or accepted drainage report may be required for temporary access control pads . a . County accepted prefabricated tracking pad b . Aggregate with base and a minimum of 70 feet long ( per Error ! Reference source not found . 6- 1 ) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 180 Figure 6-1 Tracking Control for Temporary Accesses 4 wpm- B 4,14" ao , ‘..../Lik. 1( jk..-7Lik-1(jk..-2 Or l G r � r -1 *St 471.1rilcc 40 l, c_, 0 II l,, all c 1 I ,N ' ,,• _ al _- • ,,i a. a . )7 ffre. _, Li t labzei et ai'w.wilailselllirsValltea- . aNteedkili 1 • SHALL EXTEND FULL WIDTH gm-- B OF INGRESS AND EGRESS �t OPERATION I PLAN VIEW 10• . a EXISTING GROUND ` r' ►./ 4. ve,s, ., 4 Ire we ' z /se •• c Me ‘ 4t. °a- meszipswip- tra --/ t•\ ill, or ill maillifiltrekillwiprorli ` � EXISTING PAVEMENT OR GRAVEL ROAD N`-MIRAFI FW300 GEOTEXTILE (DEPTH VARIES) OR EQUIVALENT ELEVATION SECTION xISTING GROUND • M I N ., -,71 :;,,.%,," ‘>. fi :• is-' i :f; . 0 I 0 see a 0 v , \ X.‘ • \`!\ley•. • V.<1;\. am . a . at t. v *% ' `MIRAFI FW300 GEOTEXTILE OR EQUIVALENT SECTION B - B NOTES: 1 . AGGREGATE SHALL CONFORM TO CDOT SPECIFICATIONS, SUBSECTION 208 2. THE CONTRACTOR SHALL PROTECT CURB AND GUTTER, EDGE OF PAVEME OF GRAVEL ROAD THAT CROSSES OR IS ADAJACENT TO THE ENTRANCE FR( WHILE NOT BLOCKING FLOW OF WATER. IN THE CASE THERE IS AN EXISTINC CULVERT IS REQUIRED. PROTECTION OF THE ADJACENT ROADWAY MATERIAL: ABOVE SHALL BE INCLUDED IN THE COST OF THE WORK AND NOT PAID F0$ 3. ALL MATERIALS AND LABOR TO COMPLETE THE VEHICLE TRACKING PAD INCLUDED IN THE COST OF THE WORK AND NOT PAID FOR SEPARATELY. 4. THE PAY ITEM NUMBER FOR VEHICLE TRACKING PAD (EACH) IS CDOT ST SPECIFICATION 208- 00070. WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 181 6 . 2 MS4 REQUIREMENTS Sites located in Weld County' s state - permitted Municipal Separate Storm Sewer System ( MS4 ) area are required to comply with the Grading Permit requirements as well as additional MS4 requirements . Weld County is categorized as Phase II . An MS4 is a conveyance or system of conveyances that is : • Owned by a state, county, city, town , or other public entity that discharges to waters of the United States • Designed or used to collect or convey stormwater ( including storm drains, pipes, ditches, etc . ) • Not a combined sewer • Not part of a publicly owned treatment works ( sewage treatment plant ) EPA' s Stormwater Phase II Rule established a management program that is intended to reduce the quantity of pollutants that enter MS4s from stormwater . Common pollutants include oil and grease from roadways, pesticides and fertilizers, sediment from construction sites, and discarded trash . When deposited into nearby waterways through MS4 discharges, these pollutants can impair the waterways, discourage recreational use , contaminate water supplies, and interfere with the habitat for aquatic o rganisms, fish , and wildlife . In compliance with the provisions of the Federal Water Pollution Control Act ( commonly referred to as the Clean Water Act ) , as amended ( 33 USC 1251 et seq . ) , the EPA promulgated rules establishing Phase I o f the NPDES stormwater program in 1990 . The 1990 Phase I program requires operators of medium and large MS4s ( defined as those serving populations of 100, 000 or greater) to implement a stormwater management program to control pollution . State law has similar provisions ( Colorado Water Quality Control Act, CRS 25 -8- 101 et seq ) . The 1999 Stormwater Phase II Rule extended coverage of the NPDES stormwater program to certain " small " MS4s in urbanized areas (those serving populations of 10, 000 to 100, 000 ) . Small MS4s located in u rbanized areas are defined by the Census Bureau based on the most recent Census . New urbanized areas will be identified in each subsequent Census, occurring every 10 years . Generally, Phase I MS4s are covered by individual permits, and Phase II MS4s are covered by a general permit . Each regulated MS4 is required to develop and implement a program to reduce the contamination of stormwater runoff and prohibit illicit discharges . Operators of small MS4s are required to design their programs to reduce the discharge of pollutants to the " maximum extent practicable . " In Colorado , the program is administered by the Colorado Department of Public Health & Environment ( CDPHE ) Water Quality Control Division . ( The Colorado program is referred to as the Colorado Discharge Permit System , or CDPS, instead of NPDES . ) 6 . 2 . 1 Designated MS4 Areas and Responsibilities The MS4 mapped areas arereviewed annually by Weld County and are designated by CDPHE based on population density . Currently, MS4 municipalities in Weld County include Greeley, Evans, Windsor, Firestone, Erie , LaSalle, Brighton , Longmont, and a small portion of Northglenn and Thornton . As Weld County continues to grow in population , each of these MS4 areas will continue to expand , potentially encompassing urbanized parts of Frederick and Dacono . The MS4 permit requires the County to implement a Construction Sites Program to prevent the discharge of pollutants to the MS4 from applicable construction activities . The MS4 permit also requires WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 182 a Post-Construction Program to treat stormwater runoff from applicable development sites . These responsibilities are handled through coordination between the departments of Planning and Public Works . 6 . 2 . 2 Applicability of MS4 Requirements The MS4 Permit mandates specific requirements for construction activities resulting in a land disturbance of greater than or equal to one ( 1 ) acre . The same requirements apply to land disturbance that is less than one ( 1 ) acre but is part of a larger common plan of development or sale with a planned disturbance of greater than or equal to one acre . For subdivisions, planned disturbance is equal to the cumulative potential development area as specified by Chapter 23 of the Weld County Code and/or the Master Drainage Plan for the subdivision , if more restrictive . The MS4 Permit defines construction activity as ground -surface -disturbing activity, which includes, but is not limited to, clearing; grading; excavation ; demolition ; and installation of new or improved haul roads, access roads, staging areas, stockpiling of fill materials, and borrow areas . Activities that include routine maintenance to maintain original line and grade , hydraulic capacity, or original purpose of the facility are not considered construction activities . Activities to conduct repairs that are not part of regular maintenance and activities that are for replacement are considered construction activities and are not considered routine maintenance . Repaving activities where underlying or surrounding soil is cleared , graded , or excavated as part of the repaving operation are construction activities unless they are an excluded site under Part I . E .4 . a . i . of the permit . 6. 2 .3 Required Permits 6 . 2 . 3 . 1 CDPS Construction Stormwater Permit When construction activities result in land disturbance of one ( 1 ) acre or more, or less than one acre but part of a larger common plan of development, the owner and operator must obtain a CDPS Construction Stormwater Permit, issued by CDPHE, prior to the start of land - disturbing activities . Under certain conditions, an R- Factor waiver may be obtained from CDPHE . As part of the permit, a Stormwater Management Plan ( SWMP ) must be kept onsite at all times . Additionally, the site must have a Qualified Stormwater Manager ( GSM ) , a person knowledgeable about stormwater requirements and capable of implementing the SWMP in its entirety. Refer to the CDPHE website for more information on the CDPS Construction Stormwater Permit, R- Factor Waiver, and a SWMP preparation guidance document . 6 . 2 . 3 . 2 CDPS Construction Dewatering Permit When construction activities require dewatering, the owner and operator must obtain a CDPS Construction Dewatering Permit, issued by CDPHE, prior to the start of dewatering activities . Under certain conditions, as specified in CDPHE' s Low Risk Discharge Guidance for Discharges of Uncontaminated Groundwater to Land, a dewatering permit may not be required . However, if the dewatering activity is not complying with the guidance document and/or there is a threatened discharge of pollutants to the MS4, the Department of Public Works will issue a Stop Work Order until a CDPS Construction Dewatering Permit is obtained and the threatened discharge no longer exists . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAUE 183 Refer to the CDPHE website for more information on the CDPS Construction Dewatering Permit and CDPHE' s Low Risk Discharge Guidance for Discharges of Uncontaminated CDPHE 's Low Risk Discharge Guidance for Discharges of Uncontaminated Groundwater to Land. 6. 2 . 3 . 3 Weld County Grading Permit When construction activities will result in land disturbance of one acre or more, or less than one acre but part of a larger common plan of development, the owner or operator must obtain a Grading Permit, issued by Weld County, prior to the start of land -disturbing activities . In some cases, when disturbing less than one acre within a developing subdivision , a Grading Permit may be required depending on other construction activities in the area . Additionally, a Grading Permit may be required for sites not located within the MS4 area but discharge into an MS4 drainage system . Exemptions to the Grading Permit do not apply to properties located within the MS4 area , and variances to MS4 requirements will not be granted . 6 . 2 .4 MS4 Requirements for Pre - Construction The 'allowing requirements apply to any applicable development or construction activity within the MS4 area . This includes the resubdivision of land since it is considered a " larger common plan of development . " The Department of Public Works will review each case and determine the applicability of the site and if any exclusions are approved ( see Post-Construction exclusions below ) . 6 . 2 .4. 1 Site Plan Review The following documents shall be submitted , reviewed , and accepted by Weld County staff prior to any applicable construction activity requiring a Grading Permit . In addition , construction activity not requiring a Grading Permit may be required to submit applicable documents if determined necessary to comply with MS4 requirements . 6 . 2 .4. 2 Drainage Report Drainage Reports shall be signed and stamped by a Colorado licensed Professional Engineer. A Drainage Report Checklist, provided in Appendix B, should be completed and submitted with the report . The four main components of the Drainage Report relating to MS4 requirements are : a . General Content — describing the nature of the development, basic characteristics of the site, and proposed drainage improvements designed to comply with Weld County drainage and MS4 requirements . This includes specifying the MS4 " Base Design Standard " used in the design of the permanent water quality control measure . b . Hydrology and Hydraulic Analysis — including the calculations, narratives, and design details for permanent structural control measures and associated drainage features to show compliance with the MS4 Permit' s " Base Design Standards . " c . Construction Drawings — detailing the existing and proposed drainage, permanent water quality control measure ( s ) to be installed , and specifications for structural components . d . Long-Term Operations and Maintenance Plan — for permanent water quality control measures and associated drainage features . The plan shall include frequencies of inspections and maintenance and narratives for non -structural control measures, if applicable . Refer to USDCM Volume 3 Chapter 6 for guidance on maintaining permanent water quality control measures . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 184 When designing a permanent water quality control measure and developing maintenance procedures, Public Works will conduct routine inspections for the life of the control measure to ensure proper functioning and adequate maintenance is being performed . Inspections generally occur every year; however, some sites may qualify for inspections every five years based on factors such as the control measure type/design , facility type, pollutant load , and historical compliance . If there are no structural components to visually confirm volume capacity, such as a concrete trickle channel, micro- pool, or forebay, a survey conducted by a Professional Land Surveyor may be required . Additionally, a Colorado licensed Professional Engineer shall provide confirmation of the existing volume capacity meeting the approved Drainage Report calculations . The survey and report may be required to be submitted every five years for the life of the facility . 6 . 2 .4. 3 Grading and Sediment & Erosion Control Plans Grading and Sediment & Erosion Control Plans shall be signed and stamped by a Colorado licensed Professional Engineer . A Grading Permit Checklist, provided in Appendix G , should be used in developing plans to expedite the review process . For details, refer to Section 6 . 1 . The main components of the Grading Plan and Sediment & Erosion Control Plan have been identified in Section 6 . 1 . 2 above . 6 . 2 .4.4 MS4 Pollution Prevention Plan The MS4 Pollution Prevention Plan Checklist and Manual is availablein Appendix H . The checklist shall be completed and submitted with the plan The manual contains County-approved installation and maintenance specifications for temporary control measures . Specifications for proprietary temporary control measures, such as concrete washout structures and vehicle tracking pads, shall be submitted and approved prior to use . The MS4 Pollution Prevention Plan Checklist and Manual was developed to help the Qualified Stormwater Manager ( QSM ) with implementation of structural and non - structural temporary control measures used during each phase of construction , from initial disturbance to final stabilization , to prevent the discharge of pollutants from the site . It is the QSM ' s responsibility to identify all potential pollutants onsite and to implement temporary control measures for each pollutant . A list of potential pollutants include : • Vehicle tracking of sediments • Land disturbance and storage of soils • Loading and unloading operations • Outdoor storage of construction site materials, building materials, fertilizers, and chemicals . • Bulk storage of materials • Vehicle/equipment maintenance and fueling • Significant dust- or particulate-generating processes • Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, and oils • Concrete truck/equipment washing, including the chute and associated fixtures and equipment • Dedicated asphalt/concrete batch plants or masonry mixing station • Waste sources such as sanitary waste, construction site waste, and worker trash WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE J 85 • Other non -stormwater discharges, including construction dewatering or power washing • Other areas or operations where spills can occur ( if so, specify) 6 . 2 .4. 5 Future Development For developments not requiring a Grading Permit, such as a re -subdivision of land or phased construction sites, MS4 requirements remain applicable . If no land -disturbing activities are planned , the applicant may only be required to submit a Drainage Report, including, but not limited to, the design of a peemanent water quality feature and associated drainage features and a Long-Term Operation and Maintenance Plan . Upon commencement of land -disturbing activities, additional documents, such as a Gracing Plan , Sediment & Erosion Control Plan , and MS4 Pollution Prevention Plan will be required . 6 . 2 . 5 MS4 Requirements for Construction Activity 6 . 2 . 5 . 1 Stormwater Inspections As required by the MS4 Permit, the County is required to routinely inspect construction sites at a frequency of at least every 45 days . The Department of Public Works maintains the authority to increase inspection frequencies based on historical violations . It is the responsibility of the applicant to contact the Department of Public Works to schedule the first inspection , at which time, the temporary control measures necessary to begin construction will be inspected ( I . e . perimeter control and vehicle tracking control ) . The applicant shall provide notice a minimum of seven days prior to commencing construction activity . Failure to schedule an inspection is considered a violation of MS4 requirements, and a stop work order or other enforcement actions may be pursued . During routine inspections, the inspector shall review the current site conditions using the documents submitted during the review process . Significant changes in plans may require modifications to be submitted for approval . Minor changes should be noted in the Grading Plan and Sediment & Erosion Control Plan , MS4 Pollution Prevention Plan, or SWMP, which are to be kept onsite at all times . The inspector shall assess all onsite control measures, pollutant sources, and discharge points to determine if an illicit discharge has occurred or has the potential to occur . If violations are found , the appl cant will be notified verbally, via email and/or certified mail , depending on the severity of the violations . . A compliance inspection then will be scheduled no later than 14 days from the date of the violation . If violations are not corrected by the time of the compliance inspection , and a schedule for compliance is not being followed , escalating enforcement procedures shall be followed until the site reaches compliance . This may include a formal Notice of Violation ( NOV) , the issuance of a Stop Work Orderand holding all permits for the site until violations have been corrected . If violations continue to exist, judicial enforcement responses may be pursued depending on the severity and recalcitrance of the violations . Refer to the Enforcement section below . Indicator ( drive- by) inspections may be conducted at any time to assess site conditions . However, if violations are found during indicator inspections, the applicant will be contacted to remedy the violations and to schedule a follow- up compliance inspection . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 186 When construction activity is completed , inspections shall occur at least every 90 days until the site has reached final stabilization and all temporary control measures have been removed . If the contractor is no longer associated with the site, the CDPS permit shall be transferred to the landowner, and the completed transfer shall be emailed to Public Works . A final walkthrough will be performed to release the Grading Permit . 6 . 2 . 5 . 2 Construction Enforcement Upon finding a stormwater violation that does not require emergency suspension , the inspector will verbally inform the owner and/or operator of the necessary corrective action . If the violation is corrected during the inspection , no further action is required . For all remaining violations, the inspector will notify the owner and/or operator detailing the required corrective actions, and a follow- up compliance inspection will be scheduled . Depending on the severity of the violation , alternatives to the follow- up compliance inspection may be allowed , such as submitting photos of the corrective action . When the site reaches compliance, the routine inspection frequency will resume . If violations were not corrected by the follow- up compliance inspection , an NOV will be issued , specifying a date by which compliance must be obtained to avoid further enforcement action . If corrective actions are found adequate during the compliance inspection , the routine inspection frequency will resume . If the violations detailed in the NOV were not corrected by the specified date, additional NOVs may be issued , in combination with additional enforcement actions, such as Stop Work Orders and placing holds on permits . If compliance is not being achieved through previous methods, the Department of Public Works may decide to pursue an administrative entry and seizure warrant for abatement in addition to any potential civil and/or criminal enforcement . A hearing with the BOCC will be scheduled to assess the costs of the abatement, and these costs will become a lien against the property from which the causes of violation have been remediated . Additionally, the County may, without prior notice , seek the suspension of MS4 discharge access, such as issuing a Stop Work Order, to stop an illicit discharge or threatened discharge which presents, or may present, imminent and substantial danger to the environment, to the health or welfare of persons or to any MS4 or waters of the state . If the violator fails to comply with a suspension order issued in an emergency, the Department of Public Works may take such steps as deemed necessary to prevent or minimize damage to any MS4 or waters of the state . The BOCC may assess the costs of the abatement and such costs will become a lien against the property from which the causes of violation have been remediated . A person commits an offense if the person reinstates access to the MS4 without prior approval of the Department of Public Works . For more information on enforcement procedures, refer to Weld County Code Section 8-9 . 6 . 2 .6 MS4 Requirements for Post Construction When developing a site within the MS4 area , stormwater drainage shall be treated by use of a permanent water quality control measure prior to discharging into any MS4 . The MS4 Permit allows for several exemptions; however, exemptions must be reviewed and accepted by Weld County staff prior to use . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 87 6 . 2 .6 . 1 Exemptions The following exemptions are allowed in the MS4 area : 1. . Large- Lot Single- Family Sites : A single -family residential lot, or agricultural zoned lands, greater than or equal to 2 . 5 acres in size per dwelling and having a total lot impervious area of less than 10 percent . A total lot imperviousness greater than 10 percent may be allowed when a study specific to the watershed demonstrates the expected soil and vegetation conditions are suitable for infiltration/filtration of the WQCV for the site . The maximum total lot impervious covered u nder this exclusion shall be 20 percent . 2 . Undeveloped Land : Sites with land disturbance to undeveloped land ( land with no human - made structures such as buildings or pavement ) that will remain undeveloped . 3 . Above Ground and Underground Utilities : Activities for installation or maintenance of u nderground utilities or infrastructure that does not permanently alter the terrain , ground cover, o r drainage patterns from those present prior to the construction activity . This exclusion includes, but is not limited to, activities to install , replace, or maintain utilities under roadways or other paved areas that return the surface to the same condition . This list contains the most common exemptions, but other exemptions are listed in the MS4 Permit and may be allowed . All exemptions will be approved on a case - by-case basis . 6 . 2 .6 . 2 Permanent Water Quality Control Measure Design Permanent water quality control measures must meet at least one of the " Base Design Standards" detailed in the MS4 Permit . No exemptions or variances to the standards are allowed for applicable development within the MS4 area . For the purposes of this section , the " permittee" is the landowner. The following italicized " Base Design Standards" were excerpted from the MS4 Permit, and all references made can be found within that document . The entire permit is available on the CDPHE website . 1 . WQCV Standard The control measure (s) is designed to provide treatment and/or infiltration of the WQCV and: • 100 percent of the applicable development site is captured , except the permittee may exclude u p to 20 percent, not to exceed 1 acre of the applicable development site area when the permittee has determined that it is not practicable to capture runoff from portions of the site that will not drain towards control measures . In addition, the permittee must also determine that the implementation of a separate control measure for that portion of the site is not practicable (e . g . , driveway access that drains directly to street ) . • The exclusion of up to 20 percent of the site will be approved only in extreme cases when other forms of treatment are infeasible . Use of this exclusion will not be approved if flows can be diverted to the main permanent water quality control measure, or a separate permanent water quality control measure can be installed . It is the duty of the Engineer to demonstrate the hardship and prove that alternative methods cannot be employed . Cost in this case is not considered a hardship . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF I 88 Evaluation of the minimum drain time shall be based on the pollutant removal mechanism and functionality of the control measure implemented . Consideration of drain time shall include maintaining vegetation necessary for operation of the control measure ( e . g . , wetland vegetation ) . Most commonly, applicable development will require a detention pond , sized for the 100-year storm event and releasing within 72 hours, for flood control purposes . Detention ponds designed to current standards and rainfall data meet the WQCV Standard . However, if the site drains to a detention pond designed under previous standards and/or rainfall data that do not meet the WQCV Standard , a new permanent water quality control measure is required . Additionally, a permanent water quality control measure is required even if a site qualifies for an exception to detention . In order to show compliance with this design standard , the plan must detail the percentage of the site is being captured and treated by the permanent water quality control measure . If there are any excluded areas proposed , a hardship must be demonstrated . Public Works will assess these on a case - by-case basis . Examples of permanent water quality control measures meeting the WQCV Standard include detention ponds ( with orifice plates ) , bioretention ( with underdrains ) , and sand filters ( with underdrains ) . Calculations for the WQCV Standard can be found in the USDCM , Volume 3 . 2 . Runoff Reduction Standard The control measure(s) is designed to infiltrate into the ground where site geology permits, evaporate, or evapotranspire a quantity of water equal to 60 percent of what the calculated WQCV would be if all impervious area for the applicable development site discharged without infiltration. This base design standard can be met through practices such as green infrastructure. "Green infrastructure " generally refers to control measures that use vegetation, soils, and natural processes or mimic natural processes to manage stormwater. Green infrastructure can be used in place of or in addition to low impact development principles. The Runoff Reduction Standard is most commonly used for sites qualifying for an exception to detention or sites draining to a detention pond which was not originally designed to meet the WQCV Standard . Examples of permanent water quality control measures meeting the Runoff Reduction Standard include grass swales, grass buffers, bioretention ( full infiltration ) , and sand filters ( full infiltration ) . Calculations for the Runoff Reduction Standard can be found in the USDCM , Volume 3 . 3 . Applicable Development Site Draining to a Regional WQCV Control Measure The regional WQCV control measure must be designed to accept the drainage from the applicable development site. Stormwater from the site must not discharge to a water of the state before being discharged to the regional WQCV control measure. The regional WQCV control measure must meet the requirements of the WQCV Standard listed above. The design engineer is encouraged to use guidance documents, spreadsheets and programs provided by MHFD to assist in designing the BMPs. Other software programs may be used, but the designs will be verified using the MHFD spreadsheets. The most current versions of MHFD spreadsheets can be downloaded from the MHFD website at https ://udfcd. orq/software. WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A u L 189 Control measure technology is changing constantly . Weld County will evaluate the use of newly developed control measures on a case- by-case basis when complete documentation of all assumptions is provided . Weld County reserves the right to review alternative methods and compare with other commonly used approaches, including those discussed in the USDCM . 6 . 2 .6. 3 Certificate of Occupancy Upon completion of the permanent water quality control measure , the applicant will submit an As- Built Drawing, certified by a Colorado licensed Professional Engineer, of the permanent water quality control measure and associated drainage features . An As- Built Drawing Checklist, can be found o in Appendix D . Upon receiving the As- Built drawing, Public Works will schedule an inspection of the permanent water quality control measure and associated drainage features to visually confirm site conditions with the submitted drawing . If the inspector has no concerns, the Certificate of Occupancy ( CO ) may be obtained . If not, the CO will be withheld until all concerns are addressed . For redevelopment sites or sites in violation , an ' MS4 hold ' will be placed on the parcel, under which no permits will be issued until MS4 requirements are met . 6 . 2 .6 .4 Release from Grading Permit A site reaches final stabilization when all construction , paving, and landscaping is complete, and has reached at least 70 percent permanent vegetative cover. Upon achieving final stabilization of the site and release of the CDPS Construction Stormwater Permit, a final inspection will be conducted to verify final site conditions with the previously submitted Site Plans and As- Built Drawing . When confirmation is obtained , the site can be released from the Grading Permit . If the inspector observes conditions other than in the approved documents, additional actions and/or submittals may be required . Grading Permits may be subject to a permit renewal fee . 6 . 2 . 6 . 5 Long-Term Inspections of Permanent Water Quality Control Measures Permanent water quality control measures and associated drainage features shall be routinely maintained to function properly . Long-term operation and maintenance of the permanent water quality control measure will be verified by an annual inspection or at a rate determined by Public Works staff, n ot to exceed five years . If the volume capacity of the permanent water quality control measure cannot be visually verified , such as with a concrete trickle channel or other structural marker, Public Works may require a survey to be completed by a Professional Land Surveyor. Confirmation of the volume capacity will be confirmed in a report stamped by a Colorado licensed Professional Engineer . The survey and report may be required every five years . Upon change in ownership, the new landowner will be responsible for the proper operation and maintenance of the control measure . O & M Plans may be updated at any time by contacting the Public Works Department . 6 . 2 .6 . 6 Post- Construction Enforcement When a violation is determined by an inspection, the owner will be notified either informally or formally based on the severity of the violation . Informal notification may be verbally communicated , or a written n otice will be sent, usually by email . . If corrective actions are made within a reasonable amount of time , n o further action is required . If corrective actions are not made within an agreed- upon schedule, a WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A U F` 190 formal NOV will be issued by certified mail . Additionally, an NOV may be issued if violations are severe or occur repeatedly at the site . If corrective actions are not made within the specified amount of time, the an ` MS4 hold ' will be placed on the parcel . Additionally, a hearing may be scheduled with the BOCC . If an illicit discharge has occurred or will likely occur, the Department of Public Works may take immediate action in cleaning up or preventing the contaminant from discharging into the MS4 . Specific details concerning enforcement can be found in the Weld County Code . 6 . 2 . 7 MS4 Requirements for As- Built Drawing Checklist 6 . 3 THE PURPOSE OF THIS CHECKLIST, PROVIDED IN APPENDIX D, IS TO ASSIST THE APPLICANT IN SUBMITTING THE REQUIRED AS - BUILT DRAWING FOR SITE DRAINAGE (PONDS, SWALES, INLETS, OUTLET STRUCTURES, SPILLWAYS, ETC.) IMPLEMENTED WITHIN THE MS4 AREA AS - BUILTS ARE TYPICALLY A RED - LINED COPY OF THE ORIGINAL PLANS, CLEARLY DEPICTING ALL CHANGES MADE IN THE FIELD . ELEVATIONS SHOWN IN THE PLANS SHALL BE VERIFIED THROUGH SURVEY. MATERIALS, DIMENSIONS, POND CAPACITY AND OTHER ASPECTS OF THE DESIGN SHALL BE VERIFIED BY THE ENGINEER. ADDITIONAL SHEETS MAY BE ADDED TO THE AS - BUILT DRAWINGS IF THERE IS NOT ENOUGH ROOM ON THE ORIGINAL PLAN . REVEGETATION Guidelines for revegetation in Weld County are provided in the Weed Management section of the Weld County Public Works website . For more information regarding revegetation , refer to the Revegetation chapter of the USDCM , Volume 2 , and the Temporary and Permanent Seeding Fact Sheet ( EC-2 ) of the USDCM , Volume 3 . 6 . 3 . 1 Site Preparation An initial evaluation of site conditions is necessary for successful revegetation . Site preparation activities should include, at a minimum : • Initial hydrologic evaluation • Initial weed evaluation and control • Topsoil preservation ( including existing wetland soil ) • Soil testing • Soil amendment • Seed bed preparation • Tree protection A list of noxious weeds is provided in Chapter 15, Article I of the Weld County Code . In the case that noxious weeds exist onsite, the appropriate steps need to be taken before , during, and after work is completed to control their spread . Soil amendments may be needed to improve the existing soil conditions prior to revegetating the site . Recommendations for soil amendments are provided in the Revegetation chapter of the USDCM , Volume 2 and include, but are not limited to, fertilizers, compost, peat, humates, sulfur, gypsum , lime, wood chips, and soil micro -organisms . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 191 For disturbance of soils within the Weld County right-of-way, soils should be tested to determine requirements for fertilizing and conditioning . Based upon the test results, hydraulic growth medium ( HGM ) may be required . Contact Public Works for fertilizer and HGM requirements . 6 . 3 . 2 Seeding and Planting In addition to the site preparation guidelines outlined in the Revegetation chapter of the USDCM , Volume 2 , seed mixtures should be coated with Mycorrhiza at the rate of 2 pounds per acre at the time of seeding . The Weed Management page of the Weld County Public Works website provides recommended seed mixes for use within Weld County. The design engineer is encouraged to work with Weld County Public Works in selecting a suitable seed mix . The two applicable seeding styles in Weld County are drill seeding and broadcast seeding . Drill seeding involves placing the seed in a firm seed bed just under the surface, which provides the best seed -to -soil contact and yields higher success rates . Typical application for this method uses 11 pounds to 14 pounds of pure live seed ( pls ) per acre . Broadcast seeding involves placing the seed directly to the surface of the soil , and typically uses 20 pounds to 24 pounds pls per acre . Ideal seeding dates are from April 1, or spring thaw, to June 15 and from September 15 until consistent ground freeze for non - irrigated areas . Winter and early spring seeding should not be conducted if the soil is frozen , snow covered , or wet ( muddy) . Hydro- seeding will be approved by Weld County only on a case- by-case basis . In order for a project to come to completion , it will be required that the project site achieve 70% plant density during full growing season . 6 . 3 .3 Mulching Mulching is the practice of applying a protective layer of material onto the soil surface of plantings or a seeded area . Mulching may be achieved through straw or rolled erosion control product ( RECP ) installations . If mulching with straw, the straw must be certified weed -free . Mulching will not be conducted in wetland areas . Hydromulch will be approved only on a case - by-case basis . 6 . 3 .4 Maintenance A maintenance and management plan should be established for each project to ensure successful revegetation post-construction . Recommended maintenance activities include , but are not limited to : • Weed control and long-term management • Reseeding bare areas where grasses did not establish • Repairing erosion control fabrics, if applicable • Stabilizing eroded areas, particularly following large storm events • Installing protection from animal damage • Temporary or permanent irrigation , as needed • Removing debris • Installing and/or repairing temporary fencing to control foot traffic, particularly in heavily used park areas Wetland areas usually require specific post-construction monitoring as part of the Clean Water Act Section 404 permitting process . These requirements should be coordinated with Weld County Public Works . Refer to the Revegetation chapter of the USDCM , Volume 2 for more information . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 192 The property owner/developer is fully responsible for site maintenance and revegetation . 6 . 3 . 5 Erosion Protection Design Criteria Protecting major drainage channels from erosion is critical for maintaining channel stability . Channels need to be designed so that they remain stable until they are fully constructed or vegetated . It may be necessary to install riprap, straw bales, erosion control logs, or erosion control blankets in the channels to ensure that they remain stable . The BMPs outlined in the USDCM , Volume 3 , shall be used to ensure stability . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 193 CHAPTER 7 FEMA FLOODPLAIN REQUIREMENTS All development, as defined by FEMA, shall comply with , all floodplain regulations and codes, including the need to submit a CLOMR and a LOMR to FEMA for review and acceptance if applicable . For more information regarding floodplain regulations, refer to Chapter 23 , Article XI , of the Weld County Code ; the 2022 Colorado Water Conservation Board ( CWCB ) Rules and Regulations for Regulatory Floodplains in Colorado; and Title 44 Code of Federal Regulations ( CFR ) 59, 60, and 65 of FEMA' s regulations . Floodplain - related work will be reviewed by the Weld County Department of Planning Services and a permit will be issued for all compliant submittals . For more information regarding floodplain modeling and mapping requirements refer to FEMA' s Guidance for FEMA 's Risk Mapping, Assessment and Planning . 7 . 1 BACKGROUND INFORMATION Weld County is a participant in FEMA' s National Flood Insurance Program ( NFIP ) therefore Weld County is responsible for ensuring that floodplain regulations per FEMA, the state of Colorado, and Weld County are administered . Failure to administer the floodplain regulations can result in the suspension of Weld County from the NFIP . Suspension from the NFIP results in the inability of Weld County residents to obtain flood insurance and the suspension of disaster assistance funding from FEMA in the event of a natural disaster . 7 . 2 FLOODPLAIN MANAGEMENT OBLIGATIONS Weld County has several cases that govern many of the requirements set forth in this WCECC : • The boundaries of the floodplain should be accurately determined and based on a reasonable standard . Mallett v. Mamarooneck, 125 N . E . 2d 875 ( N . Y . 1955 ) . • Adoption of a floodplain regulation to regulate flood - prone areas is a valid exercise of police power and is not a taking as long as the regulation does not go beyond protection of the public' s health , safety, morals, and welfare . Hermanson v. Board of County Commissioners of Fremont, 595 P . 2d 694 ( Colo . App . 1979 ) . • The adoption by a municipality of floodplain ordinances to regulate flood - prone areas is a valid exercise of police power and is not a taking . Morrison v. City of Aurora, 745 P . 2d 1042 ( Colo . App . 1987 ) . 7 . 3 FEMA FLOODPLAINS There are several hundred square miles of FEMA mapped floodplains in Weld County . Refer to the Flood Insurance Rate Maps ( FIRMs ) that are published by FEMA to determine if a proposed project is located within a mapped floodplain . The floodplain maps can be obtained from the FEMA Flood Map Service Center and the floodplain boundaries are depicted on the Property Portal Map maintained by Weld County . The Weld County Department of Planning Services should be contacted to determine if there have been any LOMRs or other changes to the floodplain boundaries that affect the project area . 7 . 3 . 1 Floodplain Requirements All development, as defined by FEMA, requires a Floodplain Permit ( FP ) or Floodplain Development Permit ( FHDP ) from Weld County . The applications can be found on Weld County' s Planning and Zoning WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 194 website . Contact the Weld County Department of Planning Services to determine which application is required . The designer should also be aware that a CLOMR and a LOMR are required if there is an increase greater than 0 . 00 feet or a decrease greater than 0 . 3 feet in regulatory floodways . A CLOMR and a LOMR are also required if there is an increase or a decrease greater than 0 . 3 feet in the WSEL in regulatory floodplains . Sections 4 . 7 and 5 . 7 of this WCECC discuss the criteria for constructing hydraulic structures within an open channel . All design engineering of the hydraulic structures must follow accepted FEMA methodology . Construction of hydraulic structures within FEMA floodplains must not increase the WSEL for Zone A or Zone AE . Per FEMA regulations, a Floodplain Development Permit ( FHDP ) shall be required for the construction of channels and other major drainage system components within the floodplain . It may be necessary to submit a CLOMR and a LOMR to FEMA as part of the development process . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE I 95 CHAPTER 8 TRAFFIC CRITERIA This Chapter discusses the requirements for developing and submitting Traffic Impact Studies, traffic control devices, access to county roads, access design, auxiliary lane requirements, access construction within County right-of-way, and tracking control standards . 8 . 1 TRAFFIC IMPACT STUDIES A Traffic Impact Study (TIS ) is required to analyze the effects of a proposed development or other land use action on the transportation system to determine if adequate public facilities exist to serve the proposed development, and to clearly identify any improvements required to mitigate the impacts on the : ransportation system . When a plan for development or redevelopment is submitted , the applicant is responsible for assessing the traffic impacts of the additional traffic to the surrounding transportation system under existing ( current ) , short- range and long- range horizons . If a project is adjacent to a road that is under the jurisdiction of another entity ( CDOT, City, Town , or adjacent County) , the applicant is responsible for contacting that entity to determine the traffic analysis and access approvals that may be required . Any proposed access to a State Highway will require a CDOT Access Permit and direct coordination with CDOT . 8 . 1 . 1 Traffic Impact Study Area Traffic impacts shall be analyzed within the traffic impact area . The determination of a traffic impact area is done on a case - by-case basis; however, at a minimum the limits of the study should include : 1 . Internal roads . 2 . Adjacent roads . 3 . Access locations and/or new intersections . 4 . Off-site roads to the nearest paved County collector or arterial road or state highway . S . Off-site roads where traffic from the proposed development or land use action will account for at least 20 percent of the average daily traffic upon build -out . 6 . Off-site intersections where traffic from the proposed development or land use action : a . Contributes a 10- percent impact of the peak hour traffic on any approach leg of an intersection where the intersection is operating at a level of service ( LOS ) C or better upon build -out . b . Contributes a 5- percent impact of the peak hour traffic on any approach leg of an intersection where the intersection is operating at a LOS D or worse upon build -out . c . Impacts a specific turning movement that currently does not have an auxiliary turn lane by at least 50 percent of the peak hour volume warrant for an auxiliary turn lane . 8 . 1 . 2 Preliminary Traffic Impact Analysis A preliminary traffic impact analysis (traffic narrative ) shall be submitted with every project application for the application to be considered complete . The intent of the analysis is to determine the project' s cumulative development impacts, appropriate project mitigation and improvements necessary to offset a specific project' s impacts . This analysis shall include the following information : WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 196 1 . Describe how many roundtrips/day are expected for each vehicle type : Passenger Cars/ Pickups, Tandem Trucks, Semi -Truck/Trailer/ RV ( Roundtrip = One trip in and One trip out of a site ) . 2 . Describe the expected travel routes or haul routes for site traffic . 3 . Describe the travel distribution along the routes ( e .g . 50 percent of traffic will come from the north , 20 percent from the south , 30 percent from the east, etc . ) . 4 . Describe the time of day that you expect the highest traffic volumes . Public Works will review the narrative and advise the applicant if more information or an engineered traffic impact study is required . 8 . 1 . 3 Traffic Impact Study Requirements A full TIS is required for any proposed development or land use zoned Commercial or Industrial , any residential subdivision greater than nine ( 9 ) lots, or when determined necessary by the Engineer. The TIS should address impacts to on -site and off-site roadways and highways within the County and shall be prepared , stamped , and signed by a Professional Engineer licensed in the state of Colorado . The TIS shall include, at a minimum , the following information : 1 . Describe the traffic impact area , including at a minimum those elements described in the traffic impact study area section of this document . 2 . A location map showing the development site , the boundaries of the traffic impact area , and all roads, intersections, bridges, or other roadway structures in the traffic impact area . 3 . Define the following study horizons for the Full Traffic Impact Study : the existing ( current ) , short- range, and long- range horizons . a . Existing Horizon : The intent is to establish a baseline traffic condition . b . Short- Range Horizon : The intent is to evaluate the immediate impacts of the project on the transportation system . The short- range horizon year is defined as the point of full buildout of the proposed development or land use action . If the project is proposed to occur over multiple phases, the impacts shall be analyzed at the point of full buildout of each phase . In no case shall the short - range horizon exceed five ( 5 ) years . c . Long- Range Horizon : The intent is to evaluate the impacts of the fully developed project in the context of regional transportation planning efforts . The long- range impacts are analyzed as of the end of the current Regional Transportation Plan 20-year planning horizon . 4 . Identify the existing, approved , and proposed land uses within the traffic impact area . S . Describe existing traffic conditions within the traffic impact area , including average daily traffic volumes for roadways and impacted intersections and a . m . and p . m . peak hour levels of service for intersections . a . Existing daily traffic data must be obtained from the Department of Public Works . If the data are not available for the area in question or data is outdated ( older than 24 months for daily counts or 12 months for intersection counts ) , then the designer may obtain new traffic data . Daily traffic counts must be collected over a 72 - hour period starting on a Tuesday and ending on a Thursday of a normal week, excluding any holidays or events that may skew results . Daily traffic counts must have been collected within the past 24 months . Intersection turning movement counts must be collected for at least two hours each of the morning and evening peak hours of a typical weekday (Tuesday, WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 197 Wednesday, or Thursday) and must have been collected within the past 12 months . Existing daily roadway and intersection peak hour traffic counts must be included for the study area . Any traffic counts collected for the study should be included in Appendix I . 6 . For short- range traffic projections, provide references, calculations, and data sources for all trip generation estimates . The trip generation results shall be shown in a table with the following information : a . Land Use b . Unit of Measurement (for example, per dwelling unit, per 1,000 sq . ft . , etc . ) c . Total number of units d . Trip generation rates per unit for average daily traffic and peak hour volumes e . Total number of trips generated for average daily traffic and a . m . and p . m . peak hours 7 . Short- range and long- range traffic projections must also include forecasts for the growth in background traffic 8 . Provide trip distribution estimates for the roads and intersections in the traffic impact area based on the following : Tables in the report need to show the trip generation rates used , based on the most recent version of the Institute of Transportation Engineer' s Trip Generation Manual. If no Trip Generation Manual information is available, the site -specific number of trips can be calculated based on the number of employee trips for each shift time, number of deliveries, additional trips entering/exiting, and other applicable trips that may enter and exit the site throughout a typical day . a . Vehicle Types The number or percentage of anticipated trucks should be included in the trip generation . In the analysis, a Passenger Car Equivalent ( PCE ) should be used to account for slower- moving trucks in the traffic stream . The procedures for converting trucks to PCEs can be found in the latest edition of TRB' s Highway Capacity Manual or in the CDOT State Highway Access Code . If a haul route is associated with the development, the route should be called out in the report . b . Trip Distribution The directional analysis for the site -generated traffic should be presented clearly . If internal trip reductions or pass- by trips are used in the calculations, they must be clearly documented . c . Total Proposed Volumes The total proposed trips and corresponding turning movement counts should be clearly shown for both the short- range horizon ( project opening year) and for the long- range horizon ( 20-year planning horizon ) . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 198 9 . Present the volumes for short- range and long- range traffic including the projected traffic for the proposed development or land use action for the a . m . and p . m . peak hour and average daily conditions . These volumes must include turning movements at intersections as well as volumes for roads in the traffic impact area . 10 . Analyze the adequacy of the transportation system to handle the projected traffic for short- range and long- range planning years . Key elements in this analysis should include : a . Generalized daily traffic volume level of service for roadways and intersection levels of service for a . m . and p . m . peak hours, based on the following guidance : The LOS must be analyzed at each intersection within the study area . For unsignalized intersections, the worst- movement approach must be reported . The County has e stablished LOS C as the minimum acceptable threshold at both signalized and u nsignalized intersections . If LOS C cannot be achieved in the existing, opening year, or horizon year analysis, mitigation should be recommended and documented . The existing peak hour LOS and delay calculations should be based on the procedures outlined in the latest edition of the TRB' s Highway Capacity Manual. Typically, the weekday morning and evening peak hour will be used for analysis, but if the site' s peak hours are anticipated at other times of day, the proposed peak hours of analysis should be approved by the County. The following traffic analysis scenarios must be included : • Existing ( Current ) Year, without project • Short- Range Analysis, Project Opening Year with Project Traffic • Long- Range Analysis ( 20-year planning horizon ) without Project ( Background Traffic ) • Long- Range Analysis ( 20-year planning horizon ) with Project If the project is proposed to open in phases, the analysis of multiple opening year scenarios may be required . An additional Background Traffic Project Opening Year scenario may be required if background traffic volumes are anticipated to be significantly higher than under Existing Year conditions . Each analysis scenario should be presented clearly, with graphics showing the proposed access locations, assumptions used for trip distribution , trip assignment, intersection turning movements, daily traffic volumes, and LOS . Any existing or background intersection or roadway operational and geometric deficiencies in the study area should be clearly noted . b . The appropriateness of access locations and if necessary, a traffic signal warrant analysis . Requirements for access spacing are included in Section 8 . 5 . All existing and proposed intersections within the study area should be assessed to determine if spacing criteria are met . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A i F 199 If an intersection within the study area may be signalized , a traffic signal warrant analysis should be performed based on the warrant criteria in the latest edition of the MUTCD . Both the opening year and horizon year conditions should be evaluated to determine if the intersection may meet warrants . c . The need for auxiliary lanes ( turn lanes, deceleration , and acceleration lanes ) , including explanations of how acceleration/deceleration lengths, storage lengths, and taper lengths were determined . Requirements for auxiliary lanes are included in Section 8 . 7 and are based on the CDOT State Highway Access Code Rural Highway ( Category R- B ) classification requirements . If the roadway has characteristics differing from a Rural Highway, the designer should refer to the Access Code to utilize a more appropriate classification to calculate auxiliary lane needs . All intersections and site access points within the study area should be evaluated to determine if auxiliary lane warrants are met . If auxiliary lanes are in place, the study should determine if the storage length , taper length , and deceleration/acceleration lane distances meet minimum requirements with the added site traffic . d . Sight Distance All site accesses should be evaluated to ensure sight distance minimum requirements are met based on the requirements in Section 8 . 6 . If applicable , the study should evaluate if changes to passing zones are recommended in the vicinity of the site due to the proposed development . e . Crash History A crash history and safety analysis may be required if the site is proposed to access a f. location where the County has identified a safety concern . Consultants may need to purchase third - party software, such as DiExSys, to analyze the safety performance functions of a location based on existing and proposed new traffic . If a location is found to perform at a level of service of safety greater than 3 , then improvements must be determined to reduce the level of service of safety . Weld County will accept locations that have a level of service of safety of 1, 2 , or 3 . Sites Accessing Gravel Roads If the site is proposed to access gravel roads, an assessment should be performed to determine if development of the site requires consideration of paving the road . See Section 8 . 9 for Tracking Control requirements . g . Parking Needs For non - residential development, ensure that the site has adequate on -site or on -street parking available . h . Safe Routes to School and/or School Bus Stops WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1100 For residential development, identify existing or proposed school bus stops within the study area , existing and proposed sidewalks, and note any deficiencies and proposed improvements . i . Access to Public Transit If there is public transit within the study limits, identify accessibility to public transit and safe pedestrian/ bicycle access to the nearest transit stop within half a mile of the project site . j . Haul Route If applicable, the site' s proposed haul route should be identified . Any deficiencies along the haul route ( such as pavement, bridge deficiencies, etc . ) must be called out along the haul route, even if it is outside of the project study area . 11 . Provide a summary of conclusions and recommendations from the full Traffic Impact Study, including at least the following items : a . A summary listing of traffic impacts from the proposed development on existing and proposed roads and intersections within the traffic impact area . b . A summary listing of the improvements needed to assure adequate service and safety levels on the roadway system affected by the proposed development, identify and describe each proposed improvement, how and when it will be funded , and expected completion dates . i . The TIS should clearly state recommended improvements to the site accesses, intersections, and roadway system for the short- range and long- range years . Include any auxiliary lane recommendations, modifications to existing storage bay lengths, intersections recommended to be signalized , proposed turning restrictions at intersections or access points, modifications to roadway surface, or improvements required along the roadway . ii . An updated LOS analysis should be performed where mitigation is recommended to ensure that acceptable operations can be achieved for both short- range and long- range conditions . iii . Identify and describe each proposed improvement, how and when it will be funded , and expected completion dates . 12 . Any reasonable additional information deemed necessary for review—special considerations . Public Works will review the TIS and advise the applicant if more information is needed or provide technical comments on the submittal . 8 . 1 .4 Traffic Impact Study Checklist A stand -alone checklist will be provided to developers along with the Pre-Submittal Requirements packet found in Appendix I of this document . 8 . 1 . 5 Updating Existing Traffic Impact Studies The following scenarios will require the preparation of an update ( or amendment ) to a previous study, or the preparation of an entirely new study . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A (1 F 1101 1 . When the time or circumstances of the original study fall within the parameters presented in Table 8- 1 , the applicant shall prepare the appropriate documentation identified in Table 8- 1 . 2 . When the original study was prepared for a large, complex, or phased project and was designed , organized , and written to function as a " base" or master plan document for future development applications, it must include updates to the County comprehensive plan . (These types of studies require scoping consultation with the County prior to their preparation . ) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1102 Table 8-1 Updating an Existing TIS Changes to the Original Development Access changed, or trip generation Access did not change, and trip generation did Original Report is : increased by 15% or more not increase by 15% or more Letter documenting change; include level of Amendment letter : identify and < 2 years old service discuss only items that changed ( No other traffic requirements ) Amendment letter, including : • Updated traffic counts ( daily counts taken over 72 hours ) > 2 years old New study • Revised trip generation • Revised LOS analysis • Meet all current TIS requirements 8 . 2 CHANGE IN ACCESS USE If the use of an existing access to County right-of-way changes or there is a change in the use of the property, a new Access Permit will be required , in accordance with Chapter 8, Article 14 of the Weld County Code . Change in access or property use may include, but is not limited to, change in the amount or type of traffic, structural modification, remodeling, change in use or type of business, expansion of existing business, change in zoning, change in property division , and creation of new parcels . 8 . 3 TEMPORARY ACCESS Any road access that will be closed after being used for a limited time may be considered a temporary road access, or a road that will be temporarily used for a different purpose may be considered a temporary upgrade in use . The time in use of temporary accesses will not exceed 18 months . A Temporary Access Permit may be granted only if the temporary access meets minimum County traffic safety and operational requirements ( Weld County Code Sec . 8 - 14- 10, et seq ), including sight distance and tracking control that is discussed in further detail in Section Error ! Reference source not found . . For a Temporary Upgrade in Use Access Permit, the access must meet prior use standards and regulations including use, width , and turning radii after the permit expires . 8. 4 TRAFFIC CONTROL DEVICES AND PLANS All road signs, striping, delineators, barricades, signals, and other traffic control devices will conform to the most current edition of MUTCD and any applicable Colorado supplement, as amended . The applicant will be required to install all necessary signage and will bear all expenses for the fabrication and installation of road name signs, permanent barricades, and signs for implementing the approved project design ( e .g . , one way, no parking, no outlet, stop sign, speed limit ) . Necessary signage will include signs required on County roads as a consequence of the applicant' s project, such as regulatory, guide, or warning signs . Signs and barricades will be in place prior to road acceptance . 8 .4. 1. Signage and Striping Plans All road improvement and/or land development projects must incorporate a separate signage and striping plan in accordance with the criteria of this section . Striping plans may not be required for local subdivision roads . However, sign plans are still required for all subdivisions . All signing and striping plans WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1 103 will conform to the most current edition of the MUTCD . All traffic control devices will be fabricated and installed in accordance with the MUTCD . Permanent signage and striping will be complete and in place before any new roadway is opened to the public for use . 8 .4. 1 . 1 Signage Plan Elements 1 . Show the general longitudinal location of each sign ( horizontal offset and station ) . 2 . Specify the sign legend and sign type . 3 . Specify the sign size . 8 .4. 1 . 2 Striping Plan Elements 1 . Include stripe color and type . 2 . Include lane width , taper lengths, storage lengths, etc . 3 . Include striping/skip interval . 4 . All permanent pavement marking materials, except point location markings, must meet current CDOT specifications for thermoplastic traffic marking paint unless another material is specified by the engineer and approved by the County . S . All point location markings ( stop bars, turn arrows, words, symbols, etc . ) must meet specifications . 6 . Include station and offset or dimensions for all angle points, symbol locations, and line terminations . 7 . Include stripe dimensions . 8 . Delineate raised median islands . 8 .4. 2 Striping guidance A stop line ( stop bar) should be placed a minimum of 4 feet in advance of the nearest crosswalk line at controlled intersections . In the absence of a marked crosswalk, the stop line should be placed at the desired stopping point but should not be placed more than 30 feet or less than 4 feet from the nearest edge of the intersecting traveled way . Preferred distance is 10- 12 feet from edge of traveled way . 8 .4. 3 Type and Location of Signs The Department of Public Works will make the final determination regarding the type and location of traffic control devices within the right-of-way or access easement . These controls will include traffic control signs, road name signs, delineators, and permanent barricades . 8 .4 .4 New Roadway Signage Permanent signage, unless otherwise approved by the Department of Public Works, will be installed before any new road or access easement is opened for use . 8 .4 . 5 Memorial Sign Applications A memorial sign must be requested by the victim ' s family or another sponsor with the consent of the victim ' s family, in accordance with Weld County Code, Chapter 8, Article VI , Sec . 8-6 - 180 . Upon submittal of a Roadside Memorial Sign Application with fee to the Weld County Public Works Department, Public Works will review the application for acceptance . See also Appendix 8 - L and 8- M of the Weld County Code . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1104 8 .4.6 Construction Criteria Refer to Section 10 . 9 . 1 and Section 10 . 9 . 2 for more-detailed information on construction criteria of pavement marking and traffic control devices . 8 . 5 ACCESS POINTS The Weld County Code defines an access as the place, means . or way vehicles or pedestrians shall have safe, adequate and legal ingress and egress to a lot, trail , open space , off-street parking space or use . Weld County recognizes that property owners have a right of reasonable access to the County road system . However, within an environment where population growth will increase traffic volumes and operational pressure on the general transportation system , be it rural or urban , access control is crucial to protect the public health, safety, and welfare . Access control is used to maintain smooth traffic flow, to provide road right-of-way drainage, and to protect the functional level of the County roads while meeting state, regional , local , and private transportation needs and interests . Weld County Code Sec . 8 - 14- 10, et seq ., contains the County' s Road Access Policy . Also refer to the Weld County Functional Classification Map and Transportation Plan , available on the County' s Transportation Planning webpage . An access permit application must be submitted for any new proposed access to a County- maintained road . If a property is proposed to directly access a State Highway, access must be approved and obtained by CDOT as described in Section 8 . 3 . 1 . 1 . a . If a property is proposed to directly access a road under the jurisdiction of a local municipality, access must be approved and obtained by the local municipality . If a property has frontage on two roads, it is recommended access should be obtained from the lower volume road when possible . Intersection and access spacing criteria ( as measured from centerline to centerline ) for local roads, collector roads, and arterial roads are shown in Table 8-2 . Table 8-2 Minimum Intersection & Access Spacing Criteria (feet) Access Element Arterial Collector Local Distance between intersections Signalized 2, 640 N/A N/A Unsignalized 1, 320 1, 320 330 Distance between access points and intersections 660 660 330 Distance between access points 660 330 150 Distance between access points in Subdivisions N/A N/A 75 If design criteria cannot be met for auxiliary lane requirements or if an operational threshold of LOS C cannot be maintained , the proposed access may be approved as restricted movement, as described in Section 8 . 5 . 6 . 8 . 5 . 1 Local Roadways Access standards to local roadways will be governed by Weld County recognizing that property owners have a right of reasonable access to the County road system . However, within an environment where WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE ( 105 population growth will increase traffic volumes and operational pressure on the general transportation system , be it rural or urban, access control is crucial to protect the public health , safety, and welfare . Access control is used to maintain smooth traffic flow, to provide road right-of-way drainage , and to protect the functional level of the County roads while meeting state, regional , local , and private transportation needs and interests . Weld County Code Sec . 8- 14- 10, et seq . , contains the County' s Road Access Policy . Also refer to the Weld County Functional Classification Map and Transportation Plan , available on the County' s Transportation Planning webpage . Whenever possible, shared accesses will be given priority . 8 . 5 . 2 Collector Roadways Access standards to collectors are shown in Table 8-2 . An access or new intersection onto a collector is not permitted unless it meets the spacing requirements in Table 8-2 and an alternative access or intersection to a lower classified road is not feasible . No more than one access will be allowed to an individual or to contiguous parcels under the same ownership unless it can be shown that the additional access would not be in conflict with local safety regulations; the additional access would not be detrimental to public health , safety, and welfare ; and the additional access is necessary for the efficient use of the property . 8 . 5 . 3 Arterial Roadways Access standards onto arterial roadways are shown in Table 8-2 . An access or new intersection onto an arterial is not permitted unless an access/intersection to a lower classified road is not feasible and the proposed access meets the spacing requirements in Table 8-2 and does not interfere with the location , planning, and operation of the general street system or access to nearby properties . Whenever possible, shared accesses will be given priority . No more than one access will be allowed to an individual or to contiguous parcels under the same ownership unless it can be shown that allowing only one access would be in conflict with local safety regulations; the additional access would not be detrimental to public health, safety, and welfare ; and the additional access is necessary for the efficient use of the property . Intersections will be spaced no less than one -quarter mile apart on arterials, unless such spacing is impractical or impossible due to topographic or other physical limitations as determined by the Department of Public Works . The type of access — full movement, three-quarter movement, or right- in/right-out movement — will be determined by the Department of Public Works . 8 . 5 .4 State Highway and Interstate Systems CDOT and FHWA rules and regulations will apply to all highway and interstate accesses . Weld County takes no jurisdictional authority over access onto a highway or interstate . 8 . 5 . 5 Shared Accesses Whenever possible and feasible , shared access will be provided to serve two or more adjacent properties . A shared access is to be centered on the common property line . For shared accesses, the County strongly recommends the property owner establish a written access road maintenance agreement so future owners of the properties will be aware of their requirements for shared maintenance of the access road . Shared access and utility easements shall be a minimum of 30 feet wide and shall contain a minimum 20-foot-wide, all -weather roadway . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1106 8 . 5 .6 Restricted Movement Access If the minimum spacing criteria cannot be met, or if the minimum level of service threshold of LOS C cannot be achieved , the County may require that the movements at an access be restricted to ensure traffic safety . The following types of access are most common : 1 . Full movement access . All potential movements for the access are allowed . 2 . Three -quarter access . All movements are allowed except a left turn out of the access . 3 . Right- in/ right-out access . Only right turn in and right turn out movements are allowed . 8 . 5 .7 Access Control Plans On corridors with an adopted Access Control Plan in effect, recommendations for each existing and future access location and policies that guide future access management efforts will be enforced . 8. 6 ACCESS DESIGN Access points will be designed to provide safe movement for traffic entering and traveling on roadways within the County . Like intersections, access points are conflict locations . The basic design of access points includes adequate spacing, proper alignments, and clear sight distances . 8 . 6. 1 Geometric Design Accesses shall enter onto Weld County roads at an 80- to 100-degree angle, for a minimum of one vehicle length . An access approach that is gated will be designed so that the longest vehicle ( including trailers ) using the access can completely clear the traveled way when the gate is closed . In no event will the distance from the gate to the edge of the traveled surface be less than 35 feet . Any overhead entry structures shall have at least a 14-foot, 6- inch clearance , measured from the access surface . When the access is intended for commercial or industrial use, the access radii shall accommodate the turning movements of anticipated vehicle types . AutoTURN exhibits may be required by the County if there is a safety or operational concern . Table 8-3 shows the access width and access radii for properties based on land use . Table 8-3 Access Geometry Type of Land Use Maximum Access Width at ROW Access Radii Single-family residential 24 feet wide 25 feet minimum Commercial/Industrial/Agricultural 40 feet wide 65 feet minimum Fill slopes and cut slopes will be constructed to match the slopes of the existing County road adjacent to the maximum access width as identified at the ROW line . It is desirable that all side slopes be no steeper than 4 : 1 ( H :V) . Drainage culverts are required for new access points unless otherwise approved by the County . Minimum required size is a 15- inch aluminized CMP or RCP . See Section 5 . 8 . 3 of this document for allowable culvert types . Minimum cover requirement will be 12 inches above the pipe crown to the bottom of asphalt at the edge of pavement ( for paved roads) and a minimum of 12 inches of cover above the pipe crown to the top of the finished grade (for gravel roads ) . All culverts should be sized to convey the flow water based on the existing capacity of the ditch and meet the HW/D requirements specified in Chapter 5 of this document . Figure 8- 1 shows a typical access approach . Dimensions of radius and access width should be determined by Table 8-3 , above . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 0 107 Figure 8- 1 Access Approach I I I I 15" MINIMUM FLARED END DIA. CULVERT ACCESS WIDTH _ ( SECTIONS - -- - - -Tr-- - RIGHT OF WAY - - - j - FLOW LINE r GRAVEL OR PAVED SURFACE - SHOULDER RADIUS AS REQUIRED EDG E•O F•TRAVEL-L•AN E c. WELD COUNTY ROAD 8 . 6 . 2 Access Sight Distance Accesses are stop controlled so the access sight distance discussed in this section is the distance required for vehicles to enter traffic and accelerate to the average running speed . There shall be an unobstructed sight distance along both approaches and both sides at an access ( within the right-of-way ) for distances sufficient to allow the operators of vehicles that are approaching simultaneously to see each other in time to prevent collisions at the access . All clear sight triangles must be within the public right-of-way or a sight distance easement . See also Figure 8- 2 . Distance a2 in Figure 8-2 is equal to distance a1 plus the width of the lane ( s ) departing from the intersection on the major road to the right . Distance a2 also should include the width of any median present on the major road . The appropriate measurement of distance a1 and distance a2 for departure sight triangles depends on the placement of any marked stop line that may be present and , thus, may vary with site-specific conditions . In Weld County, the typical distance behind the traveled way to the stop bar is 14 feet . b = 1 . 47Vmajortg tg Eq . 8 . 6 . 1 b = Access Sight Distance ( see Figure 8- 2 ) Vmaor = Design Speed of major road ( MPH ) tg = time gap needed for vehicle entering major road ( sec ) tg = 7 . 5 Car, 9 . 5 Single- Unit Truck, 11 . 5 Combo - Unit Truck Adjust tgfor crossing more than 2 lanes : +0 . 5/extra lane for cars +0 . 7/extra lane for trucks Also adjust tgfor starting grade of the vehicle if it exceeds 3 % +0 . 2 sec/percent grade for cars and trucks ( only for starting uphill ) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G F 1108 The value calculated should be rounded up to the nearest 5 feet . Additional information regarding sight distance for intersections and cases other than the stop control condition can be found in AASHTO' s A Policy on Geometric Design of Highways and Streets . Figure 8-2 Departure Sight Triangles at Access (Stop Control ) b b Si Weld County Rd Weld County Rd iv i t 1 t - a2 a . ; ..,,,<" Clear Sight Triangle Clear Sight Triangle Decision Point 0 Decision Point Qo N Departure Sight Triangle for Viewing Traffic Departure Sight Triangle for Viewing Traffic Approaching the Access/Driveway from the Left Approaching the Access/Driveway from the Right 8 . 6 .3 Subdivision Roads Sight Distance Roads should not have visible impediments between 3 feet and 8 feet in height at subdivision intersections within a triangular area , as shown in Figure 8-3 . Figure 8-3 Subdivision Road Sight Distance Triangle • POINT OF / EDGE OF DRIVING/ ; INTERSECTION SURFACE ( FLOWLINE) // / i 40' PROHIBITED AREA 40' --- -- -- EDGE OF DRIVING SURFACE ( FLOWLINE) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 0 109 8 . 7 AUXILIARY TURN LANES Auxiliary lanes are useful in maintaining the safety, traffic flow, and operation of a roadway or access . When auxiliary lanes are required by the County or warranted by information obtained during the development review process, the applicant is responsible for design , installation, and any purchase of right-of-way to accommodate the required lane width . Auxiliary lanes are required when unique location factors ( e .g . , roadway speed and traffic density, access volume, the volume of commercial trucks, the influence of nearby accesses, existing auxiliary lanes close to the proposed access, nearby traffic control devices, available stopping sight distance , and other topographic or roadway design factors) exist that determine the need for auxiliary lanes . Auxiliary lanes are required to mitigate specifically identified and documented locations with safety and/or operational problems . These include : • Any access where high traffic volume or lack of gaps in traffic make an auxiliary lane necessary for vehicles to safely and efficiently enter/exit the roadway . • Any locations where conditions such as horizontal or vertical curves and sight obstructions exist that cannot be removed and may negatively affect public safety or traffic operations . Auxiliary lanes typically consist of one or more of the following : transition taper, acceleration or deceleration length , and storage length ( see Figure 8-4 ) . The use of these components varies based on speed limit, through street classification , and site -specific conditions (grades ) . Figure 8-4 Auxiliary Lanes Layout REDIRECT TAPERS REDIRECT TAPERS -\ / / ACCELERATION LANE DECELERATION LANE 4rniii"...."7-..,3/4,3/4,3/43/4,...,,, DECELERATION LANE ACCELERATION LANE — TRANSITION TAPERS TRANSITION TAPERS Auxiliary turn lanes shall be installed on local , collector, and arterial roadways according to the criteria in Table 8-4, which is consistent with the requirements for Rural Highways in the CDOT State Highway Access Code . Auxiliary lanes may be also required at the County' s discretion if safety needs or unique location factors discussed above warrant the addition of an auxiliary lane . Auxiliary lane thresholds should incorporate a passenger car equivalent factor based on the existing and projected bus, truck, and combination volumes . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1110 Table 8-4 Auxiliary Lane Requirements Auxiliary Lane Criteria to be Checked Minimum Ingress Minimum Ingress Minimum Egress Minimum Egress Left Classifications Left Turns Required Right Turns Required Right Turns to Turns to Require for Left- Turn for Right-Turn Require Right- Turn Left-Turn Deceleration Lane Deceleration Lane Acceleration Lane Acceleration Lane May be required if it would benefit the Arterial 10 vph 25 vph 50 vph safety and operation of the roadway May be required if it would benefit the Collector 10 vph 25 vph 50 vph safety and operation of the roadway Generally not Generally not Local 10 vph 25 vph applicable applicable Deceleration Length Deceleration Length + Taper Length + Acceleration Length Acceleration Length Geometric Components + Taper Length + Storage ( Includes Taper) ( Includes Taper) Storage Length Length The geometric components of a deceleration lane are shown in Figure 8-5 and of an acceleration lane in Figure 8-6 . Figure 8-5 Geometric Components of A Deceleration Lane Deceleration Length Tape Length aseiStorage LeNth assimmaimmal ► Traffic Direction WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1111 Figure 8-6 Geometric Components of an Acceleration Lane ► Traffic Direction Taper Length mr Acceleration Length 8 . 7 . 1 Auxiliary Lane Length To determine the required acceleration and deceleration lane and transition taper length , see the design criteria presented in Table 8-5 and Table 8 -6 . Table 8- 5 is an excerpt taken from Table 4-5 of the State Highway Access Code, August 31 , 1998 for a Category R- B — Rural Highway . A rural highway is described as, " -iighways that have the capacity for moderate to high travel speeds and low traffic volumes providing for local rural needs . This category may be assigned to low volume minor arterials, secondary collectors and local highway sections that do not normally provide for significant regional , state or interstate travel demands . "The Category R- B meets the needs for most Weld County maintained roadways . The designer should refer to the State Highway Access Code for roadways with characteristics differing from the R- B description above . The length of the required transition taper is determined by multiplying the distance offset ( lateral shift ) by the transition taper ratio value associated with the posted speed in Table 8-6 . The beginning and ending point of all tapers shall be rounded . • Acceleration Transition tapers : The purpose of an acceleration lane and transition taper is to provide sufficient length for a vehicle to accelerate to the appropriate speed and merge into the through traffic lanes without disrupting traffic flow . Table 8-6 provides the required acceleration lane and transition taper lengths by design speed . Acceleration lane lengths in Table 8- 6 will be adjusted for a grade of 3 percent or more by the factors shown in Table 8 -7 . The total length of the acceleration lane includes the values of both the lane and transition taper . The length of a transition taper is calculated by multiplying the width of the lane by a standard ratio shown in Table 8-6 . The beginning and ending point of all tapers will be rounded . • Deceleration Lane lengths : Deceleration lengths shown in Table 8- 6 represent the estimated distance to maneuver from the lane into an auxiliary lane and brake to stop . The transition taper is calculated based on design speed and deceleration lane lengths in Table 8- 6 will be adjusted for a grade of 3 percent or more by the factors shown in Table 8-7 . The storage lane lengths will be included in the calculation , which are shown in Table 8-8 or based on the results of a Traffic Study . • Redirect or straight tapers : Redirect tapers wi I be used where an exclusive turn lane, median , or other redirection of vehicles is necessary and where redirection of the flow of traffic is necessary to accommodate the exclusive turn lane or median . Redirect tapers required for redirecting through travel lanes will be installed in conformance with Table 8-6 . If the redirect taper would WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1112 result in a horizontal curve design deficiency for the through movement, the horizontal curve will be corrected . Redirect tapers should be designed as straight tapers with the beginning and ending points rounded . • In cases where there is constrained right-of-way, restrictive topography, or limited distance between intersections, a design waiver may be obtained to construct a shorter auxiliary lane . Table 8-5 Components of Speed Change Lane Lengths for Rural Highways ( R-B) from State Highway Access Code Access Category Left-Turn Deceleration Lane Right-Turn Deceleration Acceleration Lane Lane R-B * decel . Length + storage * decel . Length * accel . length *Taper length is included within stated accel. Or decel. length Table 8-6 Acceleration/ Deceleration Lane and Taper Design Criteria and Redirect Taper for Through Lanes Acceleration/Deceleration Lane Design Criteria Posted speed limit ( MPH ) 25 30 35 40 45 50 55 60 65 Deceleration length ( ft ) 180 250 310 370 435 500 600 700 800 Acceleration length (ft ) N/A 190 270 380 550 760 960 1170 1380 Accel/Decel Transition taper ( ratio ) 7 . 5 : 1 8 : 1 10 : 1 12 : 1 13 . 5 : 1 15 : 1 18 . 5 : 1 25 : 1 25 : 1 Redirect ( Straight ) taper for Through Lanes 15 : 1 15 : 1 20 : 1 30 : 1 45 : 1 50 : 1 55 : 1 60 : 1 65 : 1 ( ratio ) Table 8-7 Grade Adjustment Factors for Acceleration Lanes Grade Posted Speed Limit ( mph ) 25 to 45 50 55 60 65 3 to 4 . 9% Up Grade 1 . 3 1 .4 1 . 5 1 . 5 1 . 7 5 to 7% Up Grade 1 . 5 1 . 8 2 . 0 2 . 3 2 . 5 3 to 4 . 9% Down Grade 0 . 7 0 . 65 0 . 65 0 . 6 0 . 6 S to 7% Down Grade 0 . 6 0 . 55 0 . 55 0 . 5 0 . 5 8 . 7 . 2 Storage Lengths The storage length for an auxiliary lane can be determined by the information summarized in Table 8-8 . These lengths are based on the average length of a passenger vehicle and the estimated turning vehicles per hour. Estimated lengths for buses, larger trucks, and recreational vehicles must be determined and submitted to the County for review, or a " passenger car equivalent" ( PCE ) should be incorporated into the storage length calculation . Use a PCE of 3 for each bus and all trucks and combinations of 40 feet in length or longer. Use a passenger car equivalent of 2 for each vehicle or combination at or over 20 feet in length but less than 40 feet . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE ( 113 Table 8-8 Auxiliary Lane Storage Lengths Auxiliary Lane Storage Lengths Turning vehicles per hour < 30 30-59 60- 100 100 200 300 Minimum required storage length (ft ) 25 40 50 100 200 300 Truck traffic generators ( ft ) 100 100 200 200 200 300 The basis for designing the length of required storage is to provide sufficient length for vehicles to queue within the lane without affecting other movements . Table 8-8 provides the required storage lengths for stop-controlled intersections . Storage lengths for signal -controlled intersections may be determined from highway capacity nomographs in the Highway Capacity Manual or may be based on the recommendations of the submitted Traffic Impact Study for the development . If the Department of Public Works determines that meeting the required storage length is impractical or will result in an unsafe condition , the minimum storage length will be based on the mean arrival rate . 8 . 7 . 3 Auxiliary Lane Conflicts The following standards also apply for auxiliary lane design . 1 . No driveway will be permitted within the transition area of any auxiliary lane . 2 . In the event that a portion of an auxiliary lane extends across one or more adjacent properties, the County may require the applicant to obtain any necessary right-of-way . 3 . In the event an auxiliary lane is constructed within 100 feet of an arterial -arterial intersection , the applicant is responsible for design , acquisition of required right-of-way, relocation of utilities, and construction of the lane to such intersection . 4 . Where two intersections have exclusive turn lanes that overlap or the ending points of the exclusive turn lanes have less than 300 feet or one - half their length of separation ( whichever is shorter) , and a significant structure or topographical feature does not preclude widening, a continuous exclusive turn lane will be constructed between the intersections to improve roadway consistency and safety, and to maintain edge of pavement continuity . 5 . If restrictive topography allows only one exclusive turn lane , normally a left-turn deceleration lane is given first priority . Where a left-turn lane is installed and the travel lanes must be redirected , an overlay of pavement is required . 8 . 8 ACCESS CONSTRUCTION All roadway access construction that affects existing structures within the County right-of-way — such as pavement, curbs, gutters, sidewalks, drainage structures, ditches, and auxiliary lanes — is required to incorporate modifications to existing structures as part of the final access design . An Access Permit is required prior to any new access construction . The Access Permit allows construction of the access without the need for obtaining a separate Right-of-Way Use Permit unless the proposed access point is located within section line County Right-of-Way or if the access is to be paved with asphalt or concrete . 8 .8 . 1 Gravel Requirements Gravel or recycled asphalt gravel base will be permitted for individual residential access or field access adjacent to County roads with gravel surfacing . The gravel surface will include a minimum of 6 inches of WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 114 compacted aggregate base course or equivalent material from the right-of-way line to the edge of the traveled roadway . Specifications for this material can be found in Section 9 . 6 . 6 . 8 .8 .2 Pavement Requirements Access pavement thickness shall match roadway pavement thickness . If required by the weather, a delay of one season in placement of hot bituminous pavement may be allowed , provided adequate gravel surfacing is substituted and maintained until asphalt placement . 8 .8 . 3 Access Drainage Accesses shall be constructed in a manner that minimizes erosion and does not result in deposition of silt and debris on the County roadway or in roadside ditches . Accesses that slope down toward the public road will be constructed to assure that water does not run onto or across the traveled public way . This may include designing the crown, borrow ditches, pans, or other elements so that they direct water to the existing drainage facilities along the road . The owner of the property shall pay for materials and the cost of installation for new access culverts whenever the installation of a culvert is made necessary by the creation of a new access from private property to a County roadway . The applicant is responsible for any alterations of the natural flow of water across private properties . 8 .8 .4 Structures For efficiency and to avoid maintenance or public safety concerns, the County reserves the right to maintain the full width of the road right-of-way without structures located thereon . Structures include, but are not limited to, fences, trash cans, gates, mailboxes, and irrigation structures regardless of whether they are physically located on the traveled portion or right-of-way will be removed from the right-of-way upon written request by the Department of Public Works . Mailboxes may be located in the public road right-of-way only where they do not create a roadside hazard , obstruct or hinder vehicular or pedestrian traffic, or interfere with road maintenance activities such as snowplowing and mowing . Mailboxes will be located at least 8 feet away from the edge of the traveled way . Wear, damage, or breakage to mailboxes, fencing, decorative items, signage, or any other appurtenances throughout the property roadside frontage due to thrown snow and inclusions from snow removal activities on a County- maintained road will not be the responsibility of the County . 8 . 9 AVERAGE DAILY TRAFFIC COUNT Volume counts are expressed as average daily traffic (ADT) counts or annual average daily traffic ( AADT) counts . ADT is the unadjusted , average number of vehicles passing in both directions at a specified location of a roadway . AADT is the term used to show the average traffic volume in both directions on a section of road , adjusted for seasonal variation . Traffic count information for pavement designs must be obtained from the Weld County Public Works Department . If the count information is not available for the area needed , then a traffic count must be completed by the designer and approved by Weld County . The count must be a 72 - hour continuous count and completed on Tuesday, Wednesday, and Thursday of a normal week ( no holidays or special events taking place ) . The traffic count cannot be a raw volume count; it must include a Vehicle Classification . If known changes to the traffic volumes exist since the latest count, such as new development or changes to existing development that could modify the counts, then a new traffic count may be warranted . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G h 1115 Table 8-9 Traffic Count Seasonal Adjustment Factors SEASONAL ADJUSTMENT FACTORS Timeframe Adjustment Factor Jan . 1—Feb . 28/29 1 . 08 Mar. 1—Apr . 4 1 . 00 Apr. 5—May 16 0 . 98 May 17—Jun . 20 0 . 96 Jun . 21—Aug. 22 0 . 94 Aug . 23—Sep . 26 0 . 94 Sep . 27—Nov . 1 0 . 97 N ov . 2—Nov. 29 1 . 04 N ov . 30—Dec. 31 1 . 08 8 .9 . 1 Vehicle Classification Vehicle classification categorizes vehicles into three types, as described below . • Lightweight vehicles : All motorcycles, cars, pickups, vans, and single/dual wheels o Class 1 through Class 3 • Single units : Buses and other units up to three axles o Class 4 through Class 7 • Combo units : Vehicles of four axles and more o Class 8 through Class 13 Error ! Reference source not found . 8-7 shows the most common types of vehicles found on the nation ' s highways . Designers can use this information to determine which vehicle classification category should be used for the vehicles identified in the traffic count . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1116 Figure 8-7 FHWA Vehicle Classification ( CDOT M-E Pavement Design Manual, Figure 3 . 6) Claes S chema Descriptor ire l' note rcytes pits 1 tom wf'eei axles i g Ieip all ca plt,s I i 2 - -- 3 ' all pickups aid 'oars 5411e/dual greets - immk-- -natio three axle I #1 000 ti. • 0- trail k y irr --, III i b us Es E '1C iE C La 'AteE } • 4v•- r O I two a.xlt. 4! ; 4 5 s ggle unit 5 lgieilltai trees r a' - r ;byte nree axle, ;, � � r � � , � tnit 1----T-41 _ Joy- Jo:1E { ei le uilt 8 ire , --_, cre 1.--------A .� t0l►r L t ess axles,�_�._ �� single trailers e iiin five ax es i ! sing.�e 13IIE #0 00 00 10 SIX or mare axles. sing*slr trailers S.. 1 1 le *1- five or less axle "" %i5 • • r*-wlt1-taa.�rs I I , i 12 I six axles, 8 • • • ,. mull -1 el:. 1 _I .,w Oil _ sevenr more ax e5 13 1 46 obese* r ultt-t err 1 le 010 —1 J ti / t illt- 401.11* /EDf Q Uiiiii nciass t 2r..E 14 - - - tierleze 1 t 15 Nat used WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G F 1 117 CHAPTER 9 SOIL INVESTIGATION AND PAVEMENT DESIGN 9 . 1 INTRODUCTION AND PURPOSE The design of a pavement structure involves the consideration of many factors and conditions —the most important being traffic volumes, vehicle classifications, design materials, existing materials, local climate , and drainage conditions . The purpose of this chapter is to give general guidance and to supplement the existing design information contained within the latest editions of the 1993 AASHTO Guide for Design of Pavement Structures and the CDOT M-E Pavement Design Manual, as well as AASHTO or ASTM Material Manuals . AASHTO 1993 should be used only for onsite roadway pavement designs and M - E should be used for any offsite pavement designs maintained by Weld County . These criteria provide the basic design procedures and reporting guidelines for flexible and rigid pavements . The final design should be based on a thorough investigation of specific project conditions, projected traffic, life - cycle economics, and on the performance of comparable projects with similar structural sections under similar conditions . An adequate pavement design will reduce long-term maintenance costs and provide a long- lasting driving surface . 9 . 2 FIELD INVESTIGATION AND SOIL SAMPLES Designers should visit each site to gather information that may help determine the appropriate design . Whether this is a new design or rehabilitation of an existing pavement, information such as current distress, drainage conditions, roughness, traffic control options, and surrounding land usage should be collected and will be used later during the actual design . 9 . 2 . 1 Testing Frequency Soil samples within the project limits will be obtained for each soil type as defined in the Soil Survey of Weld County, Colorado ( http : //websoilsurvey . nres . usda .gov/app/) or at a spacing of not more than 500 linear feet . These boring locations will include, but not be limited to, travel lanes, shoulders, auxiliary lanes, and roadside ditches . 9 . 2 .2 Sampling Procedures Borings can be performed by either an auger or core drill . The depth of each hole generally should be at least 5 feet to 10 feet, depending on the anticipated depths of cuts or fills of a new roadway . Borings for rehabilitation of existing surfaces generally can be on the lower side of the range unless major reconstructions are necessary at certain locations . All borings will be field logged and visually classified . 9 . 3 SUBGRADE TESTING 9 . 3 . 1 Classification Each boring location will be tested to determine liquid limit, plastic limit, plasticity index, and the percentage passing the U . S . Standard No . 200 sieve . Test results will be used to calculate the AASHTO Classification and Group Index using AASHTO M 145 . These data will be determined using the following methods : • Liquid limit : AASHTO T 89 or ASTM D 4318 • Plastic limit : AASHTO T 90 or ASTM D 4318 • Percent passing No . 200 sieve : AASHTO T 11 or ASTM C 117 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 0_ 18 • Gradation : AASHTO T 27 or ASTM D 422 9 . 3 . 2 Swell Test Swell potential evaluation will be required when a soil is classified as an A-6 to A-7 type . • Swell test : AASHTO T 216 or ASTM D2435 9 . 3 .3 pH and Sulfate pH and Sulfate testing will be performed at each boring location . It is important not only to identify the presence of sulfates but also the depth of occurrence . The designer or project manager should know what depths are crucial to the success of the design . • Sulfate ion content : CP- L2103 • pH of soils : AASHTO T 289 9 . 3 .4 Moisture Density Standard test methods for moisture density are described in AASHTO T 99 and AASHTO T 180 . 9 . 3 . 5 Hveem Stabilometer Representative samples will be tested to determine the subgrade support value using Hveem Stabilometer ( R-value ) testing . These values will be used in the design of the pavement section . R-value will be performed on each soil group (AASHTO classification ) but will never be less than a minimum of two per soils report . These tests will be conducted in accordance with the following procedures . We suggest performing the hydrometer testing for all applicable soil of interest since the percent silt and clay content in soil are identified as important independent variables . • R-Value : CP ( Colorado Procedure ) 3101 ( AASHTO 1190 & ASTM D 2844-07 ) where the reference documents used to develop CP 3101 Table 9-1 Test Requirement and Frequency Test Testing Frequency Notes/ Exception Liquid limit Each Boring Location Plastic limit Each Boring Location Gradation Each Boring Location AASHTO Classification Each Boring Location pH Each Boring Location Sulfate Each Boring Location Swell Each Clay Soil Type A-6 through A-7 -6 soil types Moisture — Density Per Report Bulk sample of material governing pavement design CBR or R-value See Section 9 . 3 . 5 9 .4 PAVEMENT DESIGN CRITERIA FOR ONSITE ROADWAYS Weld County' s pavement design method for onsite roadways is based on the 1993 AASHTO Guide for Design of Pavement Structures equations and CDOT guidelines . This section provides the criteria used for the design of these pavements . These criteria will ensure adequate strength and durability to carry WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1119 the predicted traffic loads for the design life of each project . Alternative designs will be considered as advances are made in pavement design methods and paving materials . Any deviation from the criteria presented in this document must be technically justified and approved by the Public Works Department . Weld County does not allow the use of full -depth asphalt paving and does not accept maintenance of any full -depth paved roads . 9 .4. 1 Design Equivalent Single Axle Loads ( ESAL) There are certain input requirements needed to obtain an 18, 000- pound ( 18 KIPS ) Equivalent Single Axle Load calculation or design ESAL . • Annual average daily traffic count ( see chapter 8 ) • Vehicle classification ( see chapter 8 ) • Traffic equivalence load factors • Traffic growth rate • Design period • Lane factor 9 .4.2 Traffic Equivalence Load Factors The equivalence load factor is a numerical factor that expresses the relationship between axle loads of the three types of vehicles . Table 9-2 presents equivalence loads factors from CDOT' s M-E Pavement Design Manual. Table 9-2 Equivalence Load Factors (CDOT M-E Pavement Design Manual, Table H . 2) 3-Bin Vehicle Classification Flexible Pavement Rigid Pavement Lightweight vehicles 0 . 003 0 . 003 Single units 0 . 249 0 . 285 Combo units 1 . 087 1 . 692 9 .4. 3 Traffic Growth Rate The number of vehicles using a road tends to increase with time . Weld County uses a 20-year growth rate to estimate the future traffic on roadways . The growth rate is applied to all of the vehicle classifications . A growth rate assumes that the AADT percent growth rate for any given year is applied to the volume during the preceding year. Contact the Public Works Department for assistance in determining an appropriate growth rate . 9 .4 .4 Lane Factor The number of vehicles or ADT on the roadway will be split according to the number of lanes in the proposed roadway . Table 9-3 lists the acceptable values . Table 9-3 Lane Factors ( Modified from CDOT M-E Pavement Design Manual, Table 3 . 3 ) Lanes per Direction Design Lane Factor One lane 0 . 60 Two lanes 0 . 45 Three lanes 0 . 309 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G l I 120 Four lanes 0 . 25 9 . 5 FLEXIBLE PAVEMENT DESIGN 9 . 5 . 1 Serviceability and Reliability The initial serviceability for asphalt at construction normally will fall in the range of 4 . 2 to 4 . 6 and generally will be assumed to be 4 . 5 . The terminal serviceability is based on the current ADT . These factors can be found in Table 9 -4 . Table 9-4 Serviceability Serviceability Loss ADT 2 . 0 >750 2 . 5 <750 The reliability factor, shown in Table 9- 5, is based on the functional classification of the roadway . Weld County' s functional classification map can be found on the transportation planning section of the Public Works Department web page . Table 9-5 Reliability Factor Functional Classification Urban/Rural Arterial 90 Collector 85 Local 80 9 . 5 .2 Standard Deviation Weld County uses an overall standard deviation of 0 . 44 for all pavement designs . 9 . 5 . 3 Drainage Factor The drainage factor shown in Table 9-6 may be incorporated into the pavement design to account for the drainage characteristics of the site . Table 9-6 Drainage Factor Percent of Time Pavement Structure is Exposed to Moisture Quality of Water Removed Levels Approaching Saturation Drainage Within : Less than 1% 1% to 5% 5% to 25% >25% Excellent 2 hours 1 . 40- 1 . 35 1 . 35- 1 . 30 1 . 30- 1 . 20 1 . 20 Good 1 day 1 . 35 - 1 . 25 1 . 25 - 1 . 15 1 . 15 - 1 . 00 1 . 00 Fair 1 week 1 . 25 - 1 . 15 1 . 15- 1 .05 1 . 00-0 . 80 0 . 80 Poor 1 month 1 . 15- 1 . 05 1 . 00-0 . 80 0 . 80-0 . 60 0 . 60 Very poor Will not drain 1 . 05 -0 . 95 0 . 95-0 . 75 0 . 75 -0 . 40 0 . 40 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1121 9 . 5 .4 Strength Coefficients The strength coefficients are used in the structural number equation to determine the thickness of the various layers of the pavement structure . Table 9-7 lists the strength coefficients for various potential components of the pavement section . Table 9-7 Strength Coefficient Strength Coefficients Component Test Criteria ( per inch of material ) Conventional Materials HMA 0 .44 See Section 9 . 6 . 3 * Existing bituminous pavement 0 . 20-0 . 40 N/A Aggregate base course 0 . 14 R-value ≥83 Aggregate base course 0 . 12 77≤ R-value <83 Aggregate base course 0 . 11 69≤ R-value <77 Existing aggregate base course 0 . 09 N/A Treated Materials Fly ash 0 . 10 7-day, 150 psi Lime treated subgrade 0 . 14 7-day, 160 psi Cement treated base 0 . 22 7-day, 100-200 psi Cement treated base 0 . 23 7-day, 200-300 psi *Falling Weight Deflectometer or CDOT structural layer coefficients of existing pavements forms will be used to determine the structural coefficient for existing bituminous pavements. 9 . 5 . 5 Pavement Thickness Full -depth pavement sections will not be allowed within the County- maintained right-of-way . A composite section of hot mix asphalt ( HMA) and free draining sub- base material will be used . Total HMA thickness will not be placed in lifts less than three times the nominal maximum aggregate size of the mix being used . 9 . 5 .6 Pavement Design All pavement design will be prepared in accordance with AASHTO and CDOT pavement design procedures . A computer-generated printout of the design and/or other design calculations must be included with the design submittal . In lieu of design , 12 inches of HMA over 12 inches of aggregate base course ( ABC ) will be the minimum . 9 . 6 MATERIAL SPECIFICATION 9 .6 . 1 General All sources of mined or manufactured materials used within the County- maintained right-of-way must be approved annually by the Public Works Department . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G E' 1122 9 .6 .2 Procedure for Material Source Approval On or before April 1 of each year, or a minimum of 14 calendar days before beginning construction , materials suppliers will supply written documentation and material test results from a materials testing laboratory . These will indicate the following : • That the material ( s ) being tested meet ( s ) the minimum specifications • The test procedure employed • The material test results A signed statement will be provided by the material suppler certifying that the materials tested are representative of the materials to be provided during the coming 365 -day period . 9 .6 . 3 Hot Mix Asphalt HMA will meet the requirements of and be placed according to Table 9 -8 below and the latest edition of CDOT' s Standard Specifications for Road and Bridge Construction . The 100 gyration mixes should be used on arterial and collector roads . 75 gyration mixes to be used on minor and major residentials roadways . HMA leveling courses, mid mats, and residential wear courses to be 64- 22 mixes with a maximum of 20% RAP used in aggregate gradation . HMA topping or wear course should be an SX 64-28 mix with a maximum of 20% RAP, on arterial and collector roads . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE ( 123 Table 9-8 Master Range Table for Hot Mix Asphalt from Table 703-4 in CDOT's Standard Specifications for Road and Bridge Construction Percent by Weight Passing Square Mesh Sieves Sieve Site ' Grading Grading Grading Grading Grading SF ST SX S SG 37.5 mm ( 1 !.4" ) 100 25 .0 mm 9i"i ( 1 " ) 19.0 mm 100 9i.1) 12 .5 nun 100 km 1 ii 1: ( 1/2" ) 9.5 mm 100 90 100 ( is 4 . 75 mm ( #4 ) 90 1 it :� 2 .36 mm 1 . 18 mm 30 - 54 ( ttlh ) 600 µm Y (#30) 300 µm (#50) 150µm (# 100) 75µm , _ I2 2 - 10 2 10 2 - 8 1 - 7 ( #200 .i These additional Form 43 Specification Screens will initially be established using values from the As Used Gradation shown on the Design Mix . 9.6.4 Portland Cement Concrete Pavement Portland Cement Concrete Pavement ( PCCP ) materials will meet the requirements of and be placed according to Table 9-9 below and the latest editions of CDOT' s Standard Specifications for Road and Bridge Construction and CDOT' s M&S Standard Plans . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1124 Table 9-9 Concrete Aggregate Gradation Table from Table 703-1 in CDOT's Standard Specifications for Road and Bridge Construction Coarse Aggregates (from AASHTO M43) Fine No. 3 No. 357 No. 4 No. 467 No. 57 No. 6 No. 67 No. 7 No, S Aggregate 50 rum , , _ _ _ 25.0 mm 50 mini turn turn 19.0mm 19.0mm 12.5mm 9.5mm 4.75 mm Sine Size to to to to to to to to to to `5.V 4.75 mm ? 0 . I ► mum 4.75 mm 4.759.5 mtn 4.75 mm 4.75 mm 2.36 mm 150 gm mm (2" to I 1 : t ( 1W' to 1Ftli (2/4 ( 1/2"" to (%" to ( to (3/s " to (#4 to (` to No. 4) #4) 3/O #4) #4) #8) # 100) 1 „) 63 mm 100 100 (2'/2" ) 50 mm ( 2 " ) 90- 100 95. - 100 100 100 7.5 mm 5 ^t ) 90- 100 95- 100 100 ( 11/2") 25.0 mm _ IT; _; ; 0 I , �_ � ;% -, ; ► 100 100 19.0 mm (}/4") 0- 15 35 - 70 90 -100 90 100 100 12.5 mm _ 5. _(,I. ► 20-55 t)c ► ION 11 1 — 9.5 mm (34") 0-5 10 i , , ) 0- 15 20-55 40-70 85 100 100 4. 75 rim 0 ( I l ) III ( 15 0 7i ) 0 15 Io : r, y f) ti I UI ( #4 ) 2.36 mm _ (#�) 0-5 t 14 ► 80-- 1 w it I . I � Illlll ( # 16 ) 0-5 50-85 600 lam 25-60 (#30) 300µm (#50) I 150µm (# 100) H ) 9.6.5 Aggregate Base Course ABC used in the pavement sections shall be crushed angular manufactured aggregate Class 6, unless otherwise approved . Class 6 Aggregate Base Course will meet the requirements in Table 9 - 10, which shows the gradation requirements, PI requirements, and LA Abrasion requirements . The minimum R- value shall be 69 . Angularity of aggregate shall have a minimum fractured faces of one or more as per ASTM D 5821 of 45% or more . Recycled Concrete Product ( RCP ) aggregate base course shall not be used as shouldering material or as an exposed layer . RCP will be covered by a subsequent layer. The liquid limit shall be as shown in Table 9- 10 and the plasticity index shall not exceed six when the aggregate is tested in accordance with AASHTO T 89 and T 90 respectively . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1125 Table 9-10 Aggregate Base Course Requirements Mass Percent Passing Square Mesh Sieves Sieve Designation LL not greater than 35 LL not greater than 30 Standard Mesh ABC ( mm ) Class 1 Class 2 Class 3 Class 4 Class 5 Class 6 Class 7 RAP ( �in ) 150 6" 100 100 4" 100 75 3" 95- 100 63 2 . 5" 100 50 2" 95- 100 100 100 37 . 5 1 . 5" 90- 100 100 25 . 4 1" 95 - 100 100 85- 100 19 3/4" 50-90 100 75 - 100 12 . 5 1/2" 55-90 9 . 5 3/8" 45-80 4 . 76 No . 4 30-65 30-50 30-70 30-65 25 -55 2 . 38 No . 8 25 -55 20-85 1 . 18 No . 16 5-55 0 . 42 No . 40 0 . 07 No . 200 3 - 15 3 - 15 20 max 3- 12 3- 15 3 - 12 5 - 15 0-5 Plasticity index I 0 0 0 < 6 <6 < 6 <6 <6 LA wear test (T96 ) 50 max 50 max 9 . 6 .6 Aggregate Surface Course ( Gravel) Aggregate used as surface course will meet the following requirements, unless otherwise approved . Furnish hard , durable particles or fragments of crushed stone, crushed slag, or crushed gravel conforming to the following : 1 . Los Angeles abrasion , AASHTO T96 40% 2 . Mechanically Fractured faces, one or more, ASTM D 5821 , crushed material , not screened , to attain fractured face45 % min . 3 . Free from organic matter and lumps or balls of clay 4 . Liquid Limit, AASHTO T89 30 max . 5 . Dust ratio : %passing # 200 assin 2/3 max . %passing #40 6 . Gradation and plasticity index, AASHTO T90 As shown in Table 9 - 11 Do not use material that breaks up when alternately frozen and thawed or wetted and dried . Obtain the aggregate gradation by crushing, screening, and blending processes as necessary . Fine aggregate , material passing the No 4 sieve, will consist of natural or crushed sand and fine mineral particles . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G 1126 Do not furnish material that contains asbestos fibers . Recycled concrete cannot be used as surfacing gravel . Table 9-11 Aggregate Surface Course Requirements Sieve Designation Mass Percent Passing Square Mesh Sieves Standard ( mm ) Mesh ( in ) Aggregate Surfacing 150 . 00 6 100 . 00 4 75 . 00 3 63 . 00 2 . 5 50 . 00 2 37 . 50 1 . 5 100 25 . 40 1 90- 100 19 . 00 3/4" 12 . 50 1/2" 55 -80 4 . 76 No . 4 45 -65 2 . 38 No . 8 33 -53 0 . 42 No . 40 15 -35 0 . 07 No . 200 4- 15 Plasticity index 6- 16 LA wear test (T96 ) 40 max 9 . 7 SOILS / PAVEMENT DESIGN REPORT The soils/pavement design report will include the following information : 1 . Vicinity map of investigated area 2 . Transparent overlay of proposed project " plan view" on vicinity and boring location drawings . 3 . Scaled drawing showing the location of borings 4 . Scaled drawing showing the estimated extent of subgrade soil types, thickness of base material, thickness of and HMA 5 . A spreadsheet showing all the factors used to calculate the design ESALs 6 . Summary sheet listing all sample designations, liquid limit, plasticity index, percent passing the No . 200 sieve, AASHTO classifications, group index, soil description, R-value, moisture content, percent soluble sulfate, and pH 7 . A discussion regarding potential subgrade soil problems, including, but not limited to, soils with swelling potential , frost-susceptible soils, groundwater, drainage considerations ( surface and subsurface ) , cold weather construction ( if appropriate ) , soluble sulfates and pH in the subgrade, and other factors or properties that could affect the design or performance of the pavement system 8 . Recommendations to alleviate or mitigate the impact of potential subgrade soil problems 9 . Pavement design alternatives for roadway 10 . Pavement mix types to be used for the project 11 . Any deviations from the County criteria and discussion/justification of the deviation, a formal request will be submitted for approval of the design alternative WELD COUNTY ENGINEERING 8z. CONSTRUCTION CRITERIA PAGE 1127 CHAPTER 10 CONSTRUCTION CRITERIA 10 . 1 GENERAL For the public safety, health , and well - being, it is crucial to ensure that proper construction practices and industry standards are followed . The construction criteria defined within this chapter will be used for any work within the County right- of-way and any infrastructure proposed for County maintenance . In this chapter, the " contractor" is the individual , company, landowner, developer, or other entity legally responsible for the construction work . Unless otherwise indicated , the term "engineer" refers to the current County Engineer or his/ her authorized representative, the term "department" refers to the Weld County Public Works Department, and the term " inspector" refers to the current Weld County lead construction inspector or his/ her authorized representative . 10 . 1 . 1 Policy on the Use of Referenced Publications The information provided herein summarizes and /or supplements minimum standards that have been prepared in great detail by CDOT. The most recent publications of the Weld County Department of Public Works Conformed Standard Special Revisions to CDOT Standard Specifications for Road and Bridge Construction and M&S Standard Plans are recognized by Weld County as being the primary documents used by transportation contractors and construction crews . However, CDOT policies represent statewide standards, which do not always satisfy local conditions . When standards differ, the most recent version of the Weld County Department of Public Works Conformed Standard Special Revisions to CDOT Standard Specifications for Road and Bridge Construction will govern followed by the instructions and guidance in this chapter will govern . All construction traffic control devices and their use must be in accordance with the latest version of the MUTCD . 10 . 1 . 2 Control of Work and Inspection The Department is responsible for oversight and inspection of construction that takes place within the County right-of-way and for infrastructure proposed for County maintenance . In addition to the primary goal of promoting public safety, the goal of County oversight — which takes the form of establishing standards and conducting inspections — is to help ensure quality construction and thereby minimize the long-term maintenance costs associated with County- maintained infrastructure . The County has the authority to impose standards on construction work and determine whether it has been constructed in accordance with approved plans . The contractor is responsible for staying informed about and complying with all federal , state , and local laws, ordinances, and regulations that may affect the work or impact those employed to do the work . The contractor will indemnify the County against any claim or liability arising from the County' s actions . Failure to meet these conditions can result in suspension of the work by the Department . The Department will have the authority to suspend work if the contractor has failed to maintain safe conditions for the public . Such notification will be presented to the contractor in written form , at which time work will cease immediately — except for any activities necessary to position traffic control devices and put other safety measures in place to leave the project site in a safe condition during the shutdown , as directed by the engineer . The engineer will be the final authority in matters related to the proper WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1129 interpretation of approved plans and will make final determinations when discrepancies in the plans or disputes between the inspector and the contractor occur . The inspector will have the authority to inspect all work and materials being used . The role of the inspector is to use acceptable engineering techniques and professional judgment to determine if the construction is being accomplished according to the methods described in the standards . The contractor will cooperate fully with inspection efforts, allow access to all parts of the work, and furnish any information required for complete and detailed inspections . Inspection by the department will not relieve the contractor or its designated representatives of the responsibility to control the work and ensure compliance with the approved plans and specifications for the project . 10 . 1 . 3 Project Acceptance and Warranty All work that does not conform to the standards and the approved plans — whether resulting from poor workmanship, use of defective materials, or lack of care — will be considered unacceptable work . Unacceptable work will be subject to removal and restoration prior to final acceptance of the project by the County . Disputes related to the acceptability of work will be subject to a final determination by the engineer . Upon written notice from the contractor of the completion of all work, the inspector will make a final inspection . If all project work is determined to be in compliance with the standards, the approved plans, the performance guarantee, the subdivision improvement agreement, and the contract agreement or other applicable agreements, the County will initiate the procedure for final acceptance and perform an inspection for final acceptance . If the inspection discloses any work as being unacceptable , the Public Works Department will notify the contractor in writing . After corrections have been made , another final inspection will be scheduled . The contractor will be responsible for maintenance and traffic control until final acceptance of the project has been granted by the Public Works Department . Final acceptance does not relieve the developer and/or contractor of a minimum two -year warranty on all workmanship and materials incorporated into the project, unless specified otherwise by the County . The warranty period will commence on the same date that written final acceptance is granted . Prior to the end of the warranty period , the inspector will arrange for the project to be inspected and will notify the contractor of any work items to be completed . 10 . 2 CONTRACTOR RESPONSIBILITIES 10 . 2 . 1 Qualifications, Insurance Requirements, and Licensing Any contractor performing work within the right-of-way will have the qualifications to complete the work in an acceptable and timely manner and will receive the necessary permit ( s) from the Public Works Department before beginning work . Contractors will be fully licensed , insured , and possess a valid IRS Taxpayer Identification Number. The Department reserves the right to suspend or deny work being performed by any contractor or business that has been determined by the engineer to be unqualified to perform construction within the right-of-way . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1130 10 .2 . 2 The contractor will indemnify the County from lawsuits and claims of any type that may occur as a result of its actions while performing work within the right- of-way. Until final acceptance of the project, the contractor will procure and maintain insurance coverage in the minimum amounts specified in the most recent version of the Weld County Department of Public Works Conformed Standard Special Revisions to CDOT Standard Specifications for Road and Bridge Construction from an insurance company authorized to do business in the State of Colorado . Pre - Construction Meetings Contractors shall be required to schedule and attend a pre -construction meeting prior to starting work on complicated projects . The engineer can waive this requirement if the project is small or straightforward and it is determined that a meeting is not necessary . Attendees at the meeting typically are the contractor' s key personnel , subcontractors, material suppliers, utility companies, material testing firms, the County inspector, and the County engineer. The meeting typically is held at least one week prior to start of construction . The pre-construction meeting agenda likely will include the following : • Exchange of contact information ( phone numbers, fax numbers, etc . ) • Applicable safety requirements, contact information , and emergency procedures • Construction traffic control requirements and methods • Construction schedule with key dates and benchmarks • Required contract paperwork ( insurance, bonds, escrow, permits, etc . ) • Material submittals and testing requirements • Special conditions and access requirements 10 .2 . 3 Permits Permitting requirements are discussed in Chapter 11 of this document . In addition to approved construction plans, Weld County often will require obtaining and adhering to all requirements of a Transport Permit, Right-of-Way Use Permit, Access Permit, Grading Permit, and Floodplain Development Permit . The contractor will be fully informed and knowledgeable of all required state and federal permits . Weld County is not responsible for ensuring the contractor has satisfied permit requirements from other agencies . However, copies of fully executed permits will be furnished to the engineer or inspector upon request . 10 .2 .4 Public and Worker Safety All work will be conducted in a manner that minimizes obstructions to traffic and pedestrians . The safety of the traveling public and adjacent landowners is the most important issue on every construction project . Contractors must inspect and maintain the project to ensure safety, as they bear the sole responsibility for any accidents or injuries related to the construction . The Department has the authority to suspend work if the contractor has failed to maintain safe conditions . The contractor will observe all rules and regulations of federal, state , and local health officials and departments . No workers are allowed to be required to work in unsafe surroundings or under conditions that are unsanitary, hazardous, or dangerous . Contractors will be fully informed and knowledgeable of WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G F 1131 all current construction safety practices and protective equipment to be used for specific work conditions . The contractor is responsible for complying with all safety regulations governed by the Occupational Safety and Health Administration ( OSHA ) . The inspector is not responsible for enforcing these regulations, but will monitor construction activities for obvious or suspected noncompliance with OSHA regulations and will report any such issues to the contractor and the engineer. If imminent danger potentially resulting in serious injury or death is identified in the construction area , and the contractor has failed to act immediately to correct the dangerous condition , the engineer can issue a written work suspension order. 10 .2 . 5 Utility Coordination When excavating or grading in the area of underground utilities, the contractor will comply with Article 1 . 5 of Title 9, Colorado Revised Statutes, " Excavation Requirements . " as modified by SB- 18- 167 . The contractor will notify all affected utilities at least two business days prior to commencing work and will contact the Utility Notification Center of Colorado ( UNCC ) at 8- 1 - 1 to have locations of UNCC- registered utilities marked onsite . All other underground facilities will be located by contacting the respective utility owner. Affected utility company representatives should be invited to the pre -construction meeting . Where the contractor' s operations are adjacent to a utility owner' s facilities, work will not commence until arrangements ( acceptable to both parties ) for the protection of the utilities have been made . The approved plans will clearly indicate those utility items that are to be relocated or adjusted by the utility owner and those utility items that are to be constructed by the contractor. The contractor will meet with the utility owners as often as necessary to coordinate and schedule relocations or adjustments . Weld County is not responsible for the actions of utility owners, and the contractor will not seek damages or claims against the County for coordination , inconvenience , delay, or damages sustained due to interference from the utility owners . 10 .2 . 6 Dust Control The contractor is responsible for dust control related to its construction project . The contractor also is responsible for compliance with the Colorado Air Quality Control Act . The majority of construction sites can achieve adequate dust control by providing a water-spray truck to keep moisture in the exposed soil . Water trucks may be required on any construction sites that disturb an area of land greater than 1 acre, or for projects that are using gravel roads as the main access to the construction site . The goal of dust control is to prevent airborne particulates ( dust ) from leaving the construction site or access roads . Damages or health issues caused by dust leaving the construction site are the sole responsibility of the contractor. The contractor will be responsible for cleaning up and removing any dirt or dust that has left the construction site . Closure of a roadway often requires the contractor to set up a designated detour route for traffic . If the detour route uses an existing gravel road , dust mitigation and road deterioration can quickly become a problem . Such detours often will require the contractor to apply a durable dust treatment, such as magnesium chloride . The department will determine the quantity, frequency, and locations of such dust treatments . The contractor will need to use a county approved vendor which has a Right-of-way Use permit with the county for the application . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1132 The inspector will monitor the construction site and let the contractor know if dust control measures are inadequate . Reasonable complaints received by the County or contractor from adjacent landowners, or the traveling public will be addressed by the contractor in 24 hours or less . Failure to respond to reasonable requests ( as determined by the County) to provide dust control or failure to provide a water truck on the construction site can result in a written suspension of work order from the engineer. 10 .2 . 7 Traffic Control During construction , the contractor will be responsible for supplying and maintaining traffic control devices according to the requirements of the MUTCD . Any work within the right-of-way requires approval of the Method of Handling Traffic ( MHT) by the department prior to work commencing . In addition , any road closure within the right-of-way that will last for three days or more requires approval by the BOCC prior to work commencing . The contractor should allow at least two weeks prior to the planned road closure to obtain required approvals from the County . The contractor' s MHT will be prepared by a person knowledgeable and qualified in the area of traffic control , who is a certified Traffic Control Supervisor (TCS ) . The MHT will be easily readable , prepared in a professional manner, and include the following elements : • A project site location map • A diagram showing the location of all traffic control devices • A tabulation of the sizes, types, and quantities of all traffic control devices • Location of all existing roads and accesses within the traffic control zone • Certifications of all TCSs and flaggers working on the jobsite Traffic control devices will be inspected by the contractor' s TCS for proper placement on at least a daily basis and will be inspected during the nighttime at least once per week . The reflective surfaces of all signs will be checked and cleaned on a regular basis, no less frequently than every two weeks . For safety reasons, the contractor will not store materials or equipment near open travel lanes . Portions of the roadway that are open to traffic will be maintained , kept clean , and kept free of snow and ice by the contractor. The inspector will monitor the traffic control set- up to ensure the MHT is being followed and to look for any problems that need to be corrected . If the inspector deems that changes to the traffic control are necessary, this will be communicated to the contractor and/or TCS . 10 .2 .8 Removal of Unacceptable or Unauthorized Work Unacceptable work resulting from any cause found to exist prior to final acceptance of the project will be removed and replaced in an acceptable manner at the contractor' s expense . The construction of transportation facilities requires a high degree of precision and quality from the contractor. These facilities will eventually be used by the traveling public, who assume that safe and predictable driving and drainage conditions exist . Failure to remove and/or replace unacceptable or unauthorized work within the right-of-way can expose the contractor to liability . The inspector is authorized to ensure the contractor is following approved plans and specifications, to identify work that is unacceptable or unauthorized , and to communicate such findings to the contractor . The contractor will correct the identified work in a timely manner. If the contractor and the inspector WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1133 disagree about whether work is unacceptable or unauthorized , the final determination will be made by the engineer. 10 . 2 .9 Record Drawings and Record Keeping Preparation and organization of project records and record ( as- built ) drawings is an important step for ensuring proper future maintenance of transportation facilities . This is especially true when the project includes construction of underground facilities . Changes in the scope of work, geometric design , structural plans, typical sections, standard plans, specifications, and corrections of design errors must be incorporated into the as- built plans . These as- built plans shall be sealed by the engineer responsible for changes . Information shown on the as-constructed plans should include, but is not limited to the following : Structures : • Show tip elevation of piling for each pier, wall , or abutment . • Show structure changes for both minor and major structures . • Show type, manufacturer, manufacturer' s project number, and shop drawing number of bridge expansion and bearing devices installed . • Show elevation and placement of brass cap benchmarks, when used . The elevation should be project specific and marked on the plans . All temporary benchmarks on the plans will be lined out . • Vertical and lateral clearances should be indicated Plan and Profile : • Show the final location of new utility placements, unknown utility discoveries, relocations, and changes . Abandoned utilities should be shown and noted . • Show all geometric revisions to alignment, super elevation , and grade . • Show significant changes in revised slope catches specifically ordered in the field • Show final locations of minor structures . • Show locations of discovered underground features, such as foundations or pipes, which are left in place . • Show detailed information on the location of all buried material within the County right- of-way or project limits . • Detail any new or deleted accesses . Drainage Plans : • Meet the requirements of the As- Built Drawing Checklist provided in Appendix D of this document Prior to final acceptance of construction work, the contractor will turn in all requested as-constructed information , materials testing information , electronic files, and submittals to the inspector for review . The As- Built drawings shall follow the requirements for As-Constructed drawings that are set for in the Weld County Department of Public Works Conformed Standard Special Revisions to CDOT Standard Specifications for Road and Bridge Construction WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1134 10 . 3 MATERIALS QUALITY CONTROL AND TESTING 10 . 3 . 1 Qualifications of Testing Personnel and Laboratories Materials Process Control testing is an important and necessary part of any successful transportation project . Testing of construction materials ( soil , concrete, asphalt, etc . ) ensures the owner and contractor that suppliers are providing the materials specified and adequate construction methods are being used . CDOT qualifications related to materials are covered extensively in CDOT' s Colorado Procedure 10 ( CP10 ) . It should be noted that Weld County does require the contractor to meet the qualifications for testing personnel described in CP10 . All process control testing by consultant or material testing firms should be done in accordance to AASHTO and ( CP ) Colorado Procedures as directed in the CDOT Field Materials Manual - OA Frequency Guide Schedule for Minimum Materials Sampling, Testing and Inspection . The AASHTO and CDOT Field Materials Manuals have developed and published detailed and specific standard procedures to be used for materials testing . The contractor will be responsible for providing material testing that meets the requirements of the applicable testing standard . The inspector will provide oversight to ensure material testing is being performed properly and that testing laboratories being used are adequate . 10 .3 . 2 Minimum Testing Types and Frequencies The contractor will make arrangements to provide material testing of the types and frequencies described in the latest version of the Weld County Department of Public Works Conformed Standard Special Revisions to CDOT Standard Specifications for Road and Bridge Construction . The inspector may accept some reduction in inspection and testing procedures under certain conditions . If the contractor does not intend to meet the minimum testing frequencies listed in the frequency guide schedule in the latest version of the Weld County Department of Public Works Conformed Standard Special Revisions to CD0T Standard Specifications for Road and Bridge Construction , it must provide a written explanation to the inspector at least 48 hours prior to start of the related construction . Examples of conditions under which the minimum testing frequencies may be reduced by the inspector could include : • Very small quantities of materials are being used . • The construction work is taking place outside of the roadway structural prism . • The construction work is temporary in nature . • The inspector has determined that construction methods being used easily exceed minimum requirements, thereby resulting in predictable passing test results . 10 .3 . 3 Material Sources and Sampling All material sources used will meet the requirements of the approved plans and specifications . If the contractor intends to use any materials that do not meet the requirements as described in the County criteria , it must provide a written description and request prior to or at the pre -construction meeting . The engineer then may choose to review the information and grant a variance prior to construction starting . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1135 The inspector will be granted access by the contractor to sample and test all material to be incorporated into the work . Failure to allow such access will result in a suspension of work order being issued by the engineer . The inspector reserves the right to request proof from the contractor that materials being delivered to the jobsite are coming directly from approved sources . All materials will be handled and delivered in a manner such that their quality and acceptability are not adversely affected during the process . Aggregates and pavement mixes will be delivered to the jobsite in trucks designed to prevent loss or segregation of materials . The contractor will be aware that if materials delivered to the jobsite show excessive segregation , disturbance, or contamination , they may be rejected by the inspector . HMA that has cooled excessively also may be rejected by the inspector. 10 . 3 .4 Required Submittals Contractor submittals given to the County for review and approval will vary for each project, depending on the scope and complexity of the work to be performed . A simple Access Permit or utility crossing may not justify multiple submittals, while a large-scale bridge or roadway construction project may require many submittals . The contractor will consult with the engineer prior to the pre -construction meeting for a specific list of required submittals . A typical large- scale project could include submission , review, and approval of the following documents : • MHTs • Construction schedule • Shop drawings or fabrication details • Concrete and asphalt mix designs • Soils laboratory test information • Manufacturer' s product data and installation instructions • Copies of required worker' s certifications and qualifications • Certificates of compliance and material samples • Documents required by County Codes or by the Planning Department 10 . 3 . 5 Soils Reports and Pavement Designs To ensure proper design of roads and bridges, the department will require the contractor to provide a soils report and associated pavement design . In certain cases, the engineer may waive these requirements . Specific requirements are described in Chapter 9 of this document . 10 . 3 . 6 Materials Rejection Materials that do not meet the requirements of the approved construction plans and specifications will be rejected by the inspector . Rejected materials will be removed from the right-of-way in a timely manner at the contractor' s sole expense . The contractor may choose to perform additional third - party materials testing in an effort to reverse the inspectors' decision . However, in no case will rejected materials be covered up or incorporated into the work without approval . In cases where the contractor and the inspector disagree on a materials rejection issue , the engineer will make the final decision . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A G F' 1136 10 .4 EXCAVATION AND EMBANKMENT 10 .4. 1 Utility Trenching and Backfill Requirements All utility trenches underneath or within 5 feet of a public roadway will be backfilled with suitable materials and mechanically compacted to not less than 95 percent of maximum density, as determined by AASHTO T99 . This work will require the contractor to arrange and pay for the applicable materials quality control testing . The exception to this requirement is underground utilities that are bored into place or installed by similar methods which do not disturb the surrounding soils . Alternative backfill u sing an approved flowable cement fill ( flow-fill ) mix design can be used instead of soil materials, e liminating the need for onsite compaction testing . Weld County Standard Flow- Fill Mix : • Slump of 7 to 10 inches - ASTM C143 • Compressive Strength F' C - 1, 000 PSI @ 28 days • ASTM 150 Type I - II , minimum 329 pounds • Course Aggregate ASTM -33 - Minimum 1 , 000 pounds • Fine Grain Aggregate ASTM -33 — Minimum 2 , 000 pounds • Air Entraining Agent ( SIKA Air) ASTM -C260 — Minimum 1 . 0 oz ./cubic yard • Water — Minimum 150 pounds All utility trenches located more than 5 feet away from a public roadway will be backfilled with suitable materials and mechanically compacted to not less than 90 percent of maximum density, as determined by AASHTO T99 . The inspector may choose to waive the requirement for materials testing in these cases if s/he believes that proper construction methods are being used to ensure good compaction, or if flow- fill is being used . The department reserves the right to perform material testing on any utility trench being constructed within the right-of-way . If the material testing performed by the department shows that the contractor has failed to meet or exceed the compaction requirements described above, the contractor will be directed to remove and recompact the backfill and/or pavement materials at its own expense . See Section 10 . 7 . 5 for Pavement Cuts and Patching Requirements . 10 .4. 2 Unsuitable Materials Soil materials used in embankment construction will be as recommended in the approved soils report for the project . Soil materials that do not meet the requirements of the soils report are identified as being " unsuitable materials" and will be removed from the jobsite . Projects that do not have an approved soils report will follow more general requirements for the materials to be used . Embankment and fill material will be free of ice, organics, trash , glass, chemicals, and other deleterious materials . When tested by a Hveem Stabilometer, the soils will have a minimum R-value of at least R-20 and a maximum dry density of not less than 120 pounds per cubic foot . 10 .4 . 3 Moisture and Density Control Moisture and density control will follow CDOT' s Standard Specifications for Road and Bridge Construction . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1137 The contractor will be responsible for material testing to confirm that proper construction methods are being used and that the moisture and density requirements are being met . Moisture and density testing requirements may be waived by the inspector in cases where the amount of embankment being constructed is small or the embankment being constructed is not intended to be used for a public roadway . However, the inspector is not authorized to waive or relax the testing requirements described in an approved soils report . 10 . 5 SUBGRADE CONSTRUCTION METHODS 10 . 5 . 1 Unsuitable Materials Suitability of subgrade materials is equal to that described for embankment materials in Section 10 .4 . 2 . Subgrade materials that are deemed unsuitable for construction will be removed from the jobsite . 10 . 5 . 2 Soft Spots Subgrade areas that cannot be constructed initially to meet compaction requirements or support traffic loads using standard , acceptable construction methods are commonly referred to as "soft spots . " Repair of soft spots typically is addressed by first trying methods that require little time and expense, then progressing to more costly methods if necessary . In cases where soft spots are numerous and extensive, where the soft spots are so bad that standard construction equipment cannot access the area , or where soft spots present a dangerous work condition , the contractor will consult a Professional Engineer or Professional Geologist for recommendations for proper construction methods . The following are some of the methods used to repair soft spots : • Scarifying/drying/ blending the onsite soils and then recompacting • Over-excavating and backfilling with suitable onsite soils • Over-excavating and backfilling with imported granular fill • Over-excavating and placing geogrid or geotextiles, then backfilling with imported granular fill • Subgrade treatment of onsite soils with cement, fly ash , or other approved materials The success or failure of any of these methods will be determined by extensive proof rolling and inspection . 10 . 5 . 3 Moisture and Density Control Subgrade moisture and compaction requirements are similar to the requirements for embankments but are a little more stringent since subgrade materials are a component of the overall roadway structural section . If the subgrade materials fail to meet the conditions required in the overall pavement design , the aggregate base and pavement sections are likely to fail prematurely . Moisture and density control for subgrade will follow CDOT' s Standard Specifications for Road and Bridge Construction . The contractor will be responsible for material testing to confirm that proper construction methods are being used and that the moisture and density requirements are being met . When the final subgrade surface elevations have been established , proofrolling and inspection will be performed before any aggregate base is placed on top of the subgrade . 10 . 5 .4 Subgrade Proof Rolling The department requires proof rolling of subgrade materials, observed by the inspector, to determine their adequacy to support heavy loads . This work typically is accomplished with a heavy rubber-tire WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1138 truck, such as a water truck, that can generate a minimum axle load of 18, 000 pounds per axle . The inspector may require the contractor to provide a certified weight ticket as proof that adequate proof rolling equipment is being used . The subgrade will be proof rolled after the required compaction has been verified with materials testing equipment and the subgrade has been graded to the required elevations called for in the plans . The inspector will be notified at least 48 hours prior to any subgrade proof rolling . No proof rolling will be accepted without the inspector or designee present . Upon approval of the proof rolling, the contractor will place the aggregate base course on top of the approved subgrade materials within 48 hours . If the contractor fails to place the aggregate base course within 48 hours or the moisture conditions of the subgrade change due to inclement weather or other conditions, proof rolling will need to be repeated . 10 . 5 . 5 Treated Subgrades Subgrade soils can be treated with cement, fly ash , lime , or other approved stabilizing agents . This approach is a cost-effective way to avoid over-excavation of unsuitable soils over large areas . Subgrade treatment also is used to raise the structural value of the soils, thereby allowing the designer to require less thickness of aggregate base course and pavement . Another reason for the use of stabilizing agents is to reduce the swell potential of certain clay soils . Specific moisture and density control requirements vary, depending on the type of stabilizing agent used . Prior to placement of any subgrade treatment, the contractor will submit a mix design to the inspector for approval . The contractor also will supply the inspector with information regarding the type of delivery, mixing, watering, grading, and compaction equipment to be used during construction . 10 . 6 BASE COURSE CONSTRUCTION METHODS 10 .6 . 1 Gradation and Moisture and Density Control Overall pavement quality, including structural longevity and riding smoothness, is greatly affected by the quality of the underlying subgrade and base course materials . Base course materials must meet specified gradation and moisture and density control requirements to adequately support the traffic loads . The department requires a minimum of 4 inches of compacted aggregate base course underneath any permanent paved road surface . Depending on the pavement design , subgrade R-value, predicted traffic loading, and other applicable factors, greater thicknesses of aggregate base course often are required . The base course provides the pavement structure with a free-draining, non -frost-susceptible material layer that distributes the traffic loads from the pavement surface to the underlying subgrade . Aggregates for bases will be crushed rock, native or crushed gravels, crushed recycled concrete, or crushed recycled asphalt materials . Base course gradation will be as specified in CDOT Specifications : Class 5 or Class 6 materials . Class 6 Aggregate Base Course typically is used for areas directly underneath the permanent paved surface . Class 5 Aggregate Base Course typically is used for "shouldering" the areas adjacent to the edges of the permanent paved surface . Shouldering materials shall not contain crushed or recycled concrete materials . Prior to any placement of materials, the contractor will submit a laboratory gradation test to the inspector verifying specifications are being met . The contractor also will grant the inspector access to any stockpiles or sources of base course to be used on the project . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1139 The maximum compacted thickness of any individual lift of base course will not exceed 6 inches . Multiple lifts will be required when the thickness is greater than 6 inches . Compaction of each layer will meet a density of at least 95 percent of the maximum density determined in accordance with AASHTO T- 180 . Water should be uniformly applied to ensure this compaction requirement has been met . The final surface elevations of the base course will be graded to within . 04' of the elevations specified on the plans . Placement shall be performed utilizing side-dump or belly dump haul equipment . With the exception of smaller area placement where material can be placed with little segregation using loader or skid steer equipment . Mixing, moisture conditioning and grading shall be done with rubber-tired equipment to prevent breakdown of aggregate and gradation . End dumping and Dozer grading is not allowed unless authorized by a Weld County Engineer. If material is stockpiled for any length of time, care should be taken in the maintenance of the pile to prevent segregation of the material . 10 .6 . 2 Base Course Proof Rolling The department requires proof rolling of base course materials under observation of the inspector to determine the adequacy to support heavy loads . This work typically is accomplished with a heavy rubber-tire truck, such as a water truck, that can generate a minimum axle load of 18, 000 pounds per axle . The inspector may require the contractor to provide a certified weight ticket as proof that adequate proof rolling equipment is being used . The base course will be proof rolled after the required compaction has been verified with materials testing equipment and the base course has been graded to the required elevations called for on the approved construction plans . The inspector will be notified at least 48 hours prior to any base course proof rolling . No proof rolling will be accepted without the inspector or designee present . 10 .6 . 3 Treated Base Courses Base courses can be treated with cement to obtain a stiffer and stronger material than an unbound base . A stiffer base reduces deflections due to traffic loads, which results in lower strains on the pavement surface . This approach can be a cost-saving measure that allows the designer to require less thickness of pavement . Cement-treated bases need to be designed for each specific project . The structural properties of cement-treated base depend on the soil/aggregate material , quantity of cement, curing conditions, and age . The contractor will be responsible for submitting a mix design to the inspector for review and approval prior to construction . Specific moisture and density control requirements vary, depending on the cement-treated base mix design . In addition to having an approved mix design , samples of the cement-treated base will be taken during construction , and laboratory tests will be conducted to verify that the minimum strength properties specified have been achieved . The contractor also will supply the inspector with information regarding the types of delivery, mixing, watering, grading, and compaction equipment to be used during construction . In addition , the inspector may require copies of certified weight tickets for the cement to verify proper quantities have been incorporated into the base course . All testing of processed cement- treated base material or its individual components, unless otherwise provided specifically in the approved construction plans and specifications, will be in accordance with the latest applicable AASHTO or ASTM material specifications . The final surface elevations of the cement-treated base course will be graded to within one -quarter inch of the elevations specified on the plans . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1140 10 .6 .4 Acceptance Prior to Paving Upon approval of the proof rolling, the contractor will place the pavement surface ( if applicable ) on top of the approved base course materials within 48 hours . If the contractor fails to place the pavement surface within 48 hours or the moisture conditions of the base course change due to inclement weather, excessive drying, or other conditions, proof rolling will need to be repeated . The inspector is responsible for giving the contractor final approval to proceed with placement of the pavement surface on roads and bridges within the right-of-way . The contractor will furnish copies of certified load tickets for the base course materials as proof that the correct type and quantity of base course was delivered to the jobsite . When the inspector determines that base course placement is acceptable, a pre - paving meeting can be held . 10 . 7 PAVEMENT CONSTRUCTION METHODS 10 . 7 . 1 Pre - Paving Meetings Pre - paving meetings are mandatory on any road or bridge project that requires placement of asphalt or concrete permanent pavement more than 500 tons of HMA Pavement or 2 , 000 SY of Concrete Pavement . The meetings will be scheduled and arranged with the inspector . Attendees at the pre - paving meeting generally include the contractor superintendent, paving foreman , materials quality control tester, TCS, material supplier representative, engineer, and inspector . The asphalt or concrete mix design will be submitted , reviewed , and approved by the inspector prior to the pre - paving meeting . Pre- paving meetings typically are held on the jobsite . Following is a partial list of the general items for discussion : • Introductions and attendance roster with contact information • Assignment of specific duties • Scheduling, construction sequencing, and traffic control requirements • Materials quality control methods and requirements • Types of hauling equipment and paving equipment to be used • Construction details, such as lift thicknesses, joint construction , and pavement striping • Conditions under which paving will cease ( bad weather, darkness, holidays, etc . ) 10 . 7 . 2 Recycled Asphalt Pavement Surfaces Weld County has constructed roads using recycled asphalt pavement ( RAP ) as the pavement surface for interim cross sections instead of gravel . This typically is accomplished as a permanent means of dust control and is less costly than HMA . Candidate roads for RAP pavement are gravel roads that have a high e nough ADT to make grading and dust control maintenance a significant effort, but low enough ADT to n ot warrant permanent HMA pavement placement . 10 . 7 . 3 Hot Mix Asphalt Surfaces Most County roads with permanent paved surfaces are constructed with HMA . This type of surfacing suits the County needs well since our road crews are knowledgeable and well equipped to properly maintain asphalt roads . The current edition of the CDOT Standard Specifications for Road and Bridge Construction, Sections 400, 403, 702 and 703 provide material specifications and construction methods generally acceptable to WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P A C F 1141 Weld County . Table 9 -8 has the Master Range gradation requirements for Grading S ( % " ) on bottom , intermediate lifts and SX (% " ) for top lift placement are acceptable . Designs will require Performance Graded Binder of 64-22 on bottom and intermediate lifts, while top lifts will have 64-28 (Table 702 - 1 in CDOT's Standard Specifications for Road and Bridge Construction ) , other binder grades must be approved in writing by Weld County Engineer. Design air voids will be targeted at 3 . 5-4 . 5 % under 100 gyrations . No more than 20% Recycled Asphalt may be used in the bottom and intermediate lifts . Top lift will utilize virgin aggregate in the mix design . No asphalt shingles can be used in the recycled asphalt products . Prior to any asphalt placement, the contactor will submit an asphalt mix design to the inspector for approval , as described in Section 401 . 02 ( a ) ( 1 ) and ( 2 ) of the CDOT Standard Specifications . The inspector reserves the right to perform a site visit and inspect the facilities of any asphalt supplier used . During construction , the contractor will furnish copies of certified load tickets for the pavement materials as proof that the correct type and quantity of pavement materials were delivered to the jobsite . The minimum and maximum layer thickness will be as specified by CDOT Specifications for the type of asphalt mix being used , or as otherwise specified in an approved pavement design report . The use of geosynthetics associated with asphalt pavement or mill/overlay operations will be approved by the engineer prior to use . 10 . 7 .4 Concrete (PCCP) Surfaces PCCP construction is encouraged for high -volume intersections, industrial developments, and heavy truck routes . CDOT Specifications Section 412 provides material specifications and construction methods generally acceptable to the department . Prior to any concrete placement, the contactor shall submit construction plans which follow all the requirements in this guide but also include a joint layout plan and a construction phasing plan . The following standards including but not limited to the following shall be included in the project : 1 . The Contractor shall also submit an optimized gradation concrete mix design to be reviewed and approved by the County . 2 . A PCCP design shall be provided using the mechanistic empirical ( ME ) design criteria . If the recommended pavement thickness is less than 9 inches, the minimum concrete thickness shall be 9 inches . If the recommended concrete pavement thickness is more than 9 inches, the greater thickness shall be used . The minimum thickness of Class 6 ABC is 6 inches unless a greater thickness is recommended by the design . 3 . A minimum of 1 layer of Tensar INTERAX NX650 geogrid or approved equivalent shall be placed beneath the Class 6 ABC and the subgrade on all PCCP project . The manufacturer' s requirements for overlap shall be followed . Additional layers of INTERAX NX650 shall be required if stability and compaction of the subgrade cannot be achieved . 4 . The concrete mix design shall contain no more than 20% fly-ash 5 . Only non -chloride High early strength concrete mix designs may be used in some situations if submitted and approved by the County prior to construction . 6 . All acceleration and deceleration lanes shall have a 4-foot PCCP shoulder and a 2 -foot gravel shoulder. The gravel shoulder shall be composed of either Class 6 ABC or RAP . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1142 7 . All other PCCP travel lanes shall have an 8-foot PCCP shoulder and a 2 -gravel shoulder . 8 . A safety edge is required for the full length of the PCCP lanes except at driveway locations . 9 . If an existing PCCP road is being widened , the existing safety edge and shoulder shall be removed prior to the construction of additional lanes . The additional lanes shall be constructed with a safety edge . 1O . The minimum 28-day flexural strength for concrete paving shall be a minimum of 65O psi . Any concrete paving found to be less than this shall be removed and replaced . 11 . All other material submittals such as aggregates, cement, joint sealant, curing compound , dowel bars, and tie bars shall be approved by the County prior to any concrete being placed . 12 . Non -flexible fusion bonded epoxy coated ( purple or black ) carbon steel bars ( dowels ) shall be used in the wheel paths for load transfer between panels . The Simplex Time Capsule or ArmorCoat dowel bars are acceptable . 13 . Dowel bar sizes vary depending on pavement thickness and expecting loading . Never to be less than 1 . 25" . 14 . All epoxy coated Tie Bars used in concrete pavement jointing will have no bare steel ends and require coating of epoxy paint prior to placement . 15 . The transition between PCCP and HMA shall follow the Weld County PCCP to HMA transition detail . 16 . Concrete paving shall be finished using a moistened doubled burlap drag for texture . Concrete texturing shall occur prior to curing compound being placed . 17 . All non -standard sized concrete panels shall be reinforced with 6-gauge welded wire mesh 18 . Concrete curing compound shall be White Water Linseed Oil Concrete Curing and Anti -spalling Compound or approved equivalent . 19 . Joint sealant shall be Dow Corning 89O SL joint sealant or approved equivalent . 2O . Pavement markings placed onto finished concrete pavement shall follow Table 1O- 1 below . Table 10- 1 Pavement Marking Types on Asphalt and Concrete Roadways Surface Type Line Type Material Type CDOT ITEM # 6" White Edge Line Modified Epoxy 627-00008 4" Yellow Edge Line Modified Epoxy 627-00008 4" Double-Yellow Centerline Modified Epoxy 627-00008 4" White Extension Line Modified Epoxy 627-00008 Existing As phalt 4 " White Skip Lane Line Modified Epoxy 627-00008 8" White Gore Area Modified Epoxy 627-00008 8" White Channelizer Modified Epoxy 627-00008 8" White Lane Drop Modified Epoxy 627-00008 8" White Double- Left Guide Modified Epoxy 627-00008 WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1 143 Preformed Thermoplastic ( Inlaid ) Stop Bar/Xwalk or Preformed Plastic Type I 627-30411 or yp 627-30328 ( Inlaid ) Preformed Thermoplastic ( Inlaid ) 627-30407 or Word Message/Symbol or Preformed Plastic Type I yp 627-30323 ( Inlaid ) 6" White Edge Line Modified Epoxy 627-00008 4" Yellow Edge Line Modified Epoxy 627-00008 4" Double-Yellow Centerline Modified Epoxy 627-00008 4" White Extension Line Modified Epoxy 627-00008 4" White Skip Lane Line Modified Epoxy 627-00008 8" White Gore Area Modified Epoxy 627-00008 New Asphalt 8" White Channelizer Modified Epoxy 627-00008 8" White Lane Drop Modified Epoxy 627-00008 8" White Double- Left Guide Modified Epoxy 627-00008 Sto Bar/Xwalk Preformed Thermoplastic ( Inlaid ) 627-30411 or p or Preformed Plastic Type I ( Inlaid ) 627-30328 Word Messa e/S mbol Preformed Thermoplastic ( Inlaid ) 627-30407 or g y or Preformed Plastic Type I ( Inlaid ) 627-30323 6" White Edge Line Preformed Plastic Type II ( Inlaid ) 627-02010 4" Yellow Edge Line Modified Epoxy 627-00008 4" Double-Yellow Centerline Modified Epoxy 627-00008 4" White Extension Line Modified Epoxy 627-00008 4" White Skip Lane Line Preformed Plastic Type II ( Inlaid ) 627-02010 8" White Gore Area Modified Epoxy 627-00008 Existing & New 8" White Channelizer Preformed Plastic Type II ( Inlaid ) 627-02010 Concrete 8" White Lane Drop Preformed Plastic Type II ( Inlaid ) 627-02010 8" White Double- Left Guide Preformed Plastic Type II ( Inlaid ) 627-02010 Preformed Thermoplastic ( Inlaid ) Stop Bar/Xwalk or Preformed Plastic Type I 627-30411 or yp 627-30328 ( Inlaid ) Preformed Thermoplastic ( Inlaid ) Word Message/Symbol or Preformed Plastic Type I 627-30407 or yp 627-30323 ( Inlaid ) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA P AG I . 1144 Modified Epoxy — Yellow with Rollover Curb in Roundabouts 627-00008 reflective beads 21 . For epoxy pavement markings, the concrete curing compound must be removed along the marking layouts prior to placement of the epoxy . This can be accomplished using pressurized water or other methods as approved by the County . The County reserves the right to perform a site visit and inspect the facilities of any material supplier used during construction . The contractor shall furnish copies of certified load tickets for the pavement materials as proof that the correct type and quantity of pavement materials were delivered to the jobsite . Traffic control requirements for PCCP construction are a major concern because of the concrete curing time requirements . 10 . 7 . 5 Pavement Cut and Patching Requirements Some roadways in Weld County have a " No Cut" policy in place . Consult with the Public Works Department to find out which roads fall under this policy . Construction work that requires removal of existing paved surfaces will require replacement with similar new pavement materials within a period of 48 hours, unless otherwise approved by the inspector. Traffic control devices will not be removed until after the paved surface has been replaced . Removed RAP surfaces will be replaced with HMA . Where pavement is to abut existing pavement, the existing pavement shall be removes to a neat vertical line, using a saw or other method as approved , to create a clean construction "T-Joint" . The contractor will also be required to paint the edge with diluted emulsified asphalt ( slow setting ) prior to paving operations . The rate of application shall be as determined by the engineer at the time of application . Contractor shall mill existing roadway to a minimum depth of 2 inches . The milling shall be a minimum of 2 feet wide or a greater width so that the joint will not fall within the intersecting travel lane wheel path . Construction in the winter will require temporary asphalt patching using cold - mix materials, then returning to the site to reconstruct with permanent patching using hot- mix materials when weather conditions allow . All pavement removals will be saw-cut a minimum of 1 foot wider than the patching area . The new pavement patch material will be placed and compacted to a thickness at least 1 inch greater than the adjacent in - place pavement . The minimum dimension of both length and width of any pavement patch will be at least 4 feet to ensure adequate compaction can be obtained . The inspector may choose to waive the requirement for pavement surface materials testing if they believe that proper construction methods are being used to ensure good compaction . Pavement cut and patching requirements for concrete pavements will require review and approval by the inspector . Concrete patching typically requires insertion of steel dowel bars into the adjacent pavement . Proper curing and jointing methods also must be used . Improper construction of pavement patches is a problem in Weld County . Poor construction methods may result in dangerous bumps or dips in the traveled roadway . If such conditions are identified by the department within two years after construction , the contractor will be notified in writing to reconstruct WELD COUNTY ENGINEERING 8z, CONSTRUCTION CRITERIA PAGE 1145 the pavement patch properly . Failure to meet the conditions described in the written notice from the department can result in emergency repairs being performed by County crews . In such cases, the contractor will be invoiced to reimburse the County for all costs associated with the road repairs . 10 . 8 STRUCTURES AND DRAINAGE FEATURES 10 .8 . 1 Bridges Unless otherwise approved by the engineer, bridges will be designed and constructed according to the most current requirements of AASHTO ' s LRFD Bridge Design Specifications, CDOT' s Bridge Design Manual, CDOT Standard Specifications, and CDOT Standard Plans . If alternate designs or construction methods are being proposed by the contractor, the engineer will provide specific submittal requirements . The design and construction of any bridge within the County right-of-way will be overseen by a Professional Engineer licensed in the state of Colorado . 10 .8 . 2 Culvert and Pipe Installation Culvert and pipe installation will be completed according to the requirements of CDOT Specifications Section 603 and Standard Plans, unless otherwise described in Chapter 5 . 6 .4 and Chapter 5 . 8 of this document . Pipes constructed in right-of -ay for private driveway access in rural areas will be at least CMP, or an approved equal , and will have a minimum diameter of 15 inches . Pipes constructed under the travel lanes of a new public roadway will be RCP, or an approved equal , and will have a minimum diameter of 15 inches . All culverts and pipes must be installed with a minimum of 12 inches of cover above the pipe crown and bell to the bottom of asphalt at the edge of pavement ( for paved roads ) and a minimum of 12 inches of cover above the pipe crown to the top of the finished grade ( for gravel roads ) . If 12 inches of cover is not possible, the culvert material must be rated for a minimum of HS- 20 loading or the largest expected loads crossing it ( i . e . , oil rigs, semi -trucks, etc . ) . The contractor must provide shop drawings for any precast concrete box culvert ( CBC ) , which will be reviewed and approved for use by the engineer. HDPE, ADS, or other plastic pipes that cannot withstand fire will not be allowed . It will be the responsibility of the contractor to protect pipe materials from damage during shipping, unloading, and installation . Any damaged pipe materials ( as determined by the inspector) will be removed from the jobsite . The construction elevation tolerance for pipes will be within 0 . 5 inches of the design elevation called for on the approved plans . 10 .8 . 3 Curbs, Gutters, and Construction will be according to the requirements of CDOT Specifications Section 609 and Standard Plans, or as otherwise described in Chapter 5 of this document . All curbs, gutters, and crosspans will be constructed of CDOT Class D concrete or an approved equal . All gutters and cross pans shall be 8" thick minimum . Asphalt curbs are permitted for bridge construction only . All outflow curb and gutter will be CDOT Type 2 — Section IB, unless otherwise approved . All inflow curb and gutter will be CDOT Type 2 — Section IIB, unless otherwise approved . All mountable curb shall be CDOT Type 2 Section IM or Section IIM , unless otherwise approved . All crosspans will be CDOT Gutter Type 2 with a minimum thickness of 6 inches, unless otherwise approved . The minimum vertical slope for all gutters and crosspans will be 0 . 5 percent . Minimum width of 8 feet . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1146 10 .8 .4 Concrete Structures, Manholes, and Inlets Construction will be according to the requirements of CDOT Specifications Section 601 and Standard Plans, or as otherwise described in Chapter 5 . 6 of this document . All irrigation structures will be reviewed and approved by the applicable irrigation company or board prior to construction . All concrete structures, manholes, and inlets will be constructed with steel reinforcement as shown on the approved construction plans . The contractor will be responsible for concrete quality control testing for all cast- in - place concrete construction . The contractor will request an inspection of the concrete formwork by the inspector a minimum of 24 hours prior to concrete placement . 10 .8 . 5 Retaining Walls and Slope Stabilization Measures Any retaining walls 4 feet tall or higher that are to be constructed in the right-of-way will be designed ( and designs will be stamped ) by a Professional Engineer licensed in the state of Colorado . The contractor will submit detailed plans for approval by the department prior to construction . Retaining wall foundations must follow the recommendations provided by the geotechnical engineer. Modular block retaining walls will be constructed per the manufacturer' s specifications . Retaining walls will be located such that they ensure adequate clear distance from the wall to the edge of the roadway and so do not pose a risk to the traveling public . Any retaining wall constructed in an urban or residential area and greater than 4 feet in height will incorporate a railing or fence for fall protection . Non -structural erosion control measures for slopes ( blankets, turf reinforcement mats, etc . ) will be installed per the manufacturer' s specifications . Structural slope stabilization measures ( riprap, gabions, soil anchors, slope mattresses, etc . ) will be designed , and designs will be stamped , by a Professional Engineer licensed in the state of Colorado . The contractor will submit detailed plans for approval by the department prior to construction . 103 OTHER ROADWAY FEATURES 10 .9 . 1 Pavement Markings All roadways and bridges constructed will receive permanent pavement markings ( striping ) prior to the construction traffic control devices being removed . The contractor will ensure that all pavement markings have been designed and located according to the requirements of the MUTCD . All permanent line striping will be done with epoxy paint materials applied according to the manufacturer- recommended methods at 15 mils minimum thickness, unless otherwise approved by the department . Both pavement and air temperatures will be at least 50 degrees and rising at the time of pavement marking . All permanent words, symbols, stop bars, crosswalks, etc . , will be pre-formed thermoplastic pavement markings capable of being affixed to the asphalt pavement surface by heating, unless otherwise approved by the department . The minimum pavement and air temperature will be as recommended by the manufacturer. The contractor will submit a copy of the manufacturer installation recommendations to the inspector prior to application . 10 .9 . 2 Traffic Control Devices (Signs and Signals) Installation of all permanent traffic control devices within the right-of-way is to be approved and overseen by the department . Traffic control device materials and manufacturers will meet the requirements of CDOT Specifications Section 713 and the latest version of the MUTCD . Installation of WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1147 traffic control devices will meet the requirements of CDOT Specifications Section 614 and the latest version of the MUTCD . Construction of traffic signals within the right-of-way with the intention of turning over ownership of the traffic signal to the County will require specific design guidance and approval by the department . 10 .9 . 3 Trees and Plantings Weld County does not encourage the placement of any trees or plantings within the right-of-way that require an irrigation system . Any trees or plantings proposed to be used will be able to survive under non - irrigated conditions . Trees and plantings will be located such that they do not present a safety hazard to the traveling public by ensuring adequate clear zone distance from the trees and plantings to the edge of the roadway . Trees and plantings will be of the species and varieties previously approved for use by the department . The contractor will obtain certificates of inspection of plant materials that are required by federal , state, or local laws, and will submit the certificates to the department for approval prior to planting . All delivered plant materials will be free from plant diseases and insect pests . All plant materials are subject to the two -year warranty period . The contractor is responsible for removing and replacing any dead plant materials that have been identified by the department prior to the end of the warranty period . 10 .9 .4 Sidewalks and Trails Any permanent sidewalk, bikeway, or trail within the right-of-way will be constructed with concrete or HMA, with a minimum thickness of 4 inches . The minimum width of the completed surface will be 5 feet . All completed surfaces will have a maximum cross slope of 1 . 8 percent to ensure proper drainage and comply with the Americans with Disabilities Act ( ADA ) . Sidewalks will be constructed with concrete curb ramps and will comply with ADA requirements . Before any surfacing is placed , clearing and grubbing, tree removal , grass and brush removal , and topsoil removal will be completed . The existing ground then will be thoroughly compacted to not less than 90 percent of maximum density as determined by AASHTO T99 . Materials testing requirements may be waived by the inspector if the amount of sidewalk being constructed is minimal or the construction methods being used are obviously adequate to ensure required results . 10 .9 . 5 Guardrails All new guardrail placed within the right-of-way will be CDOT Midwest Guardrail System ( MGS ) . Any contractor installing guardrail will be pre -qualified with CDOT for this specific type of construction ( work type 14 ) . The contractor will be responsible for providing and maintaining traffic control devices until the guardrail construction has been entirely completed , inspected , and approved for use by the inspector. 10 .9 . 6 Fences New fences constructed within the right-of-way will be in accordance with CDOT Specifications Section 607 and Standard Plans No . M -607- 1 ( Wire Fences and Gates ) . In cases where a contractor is replacing an existing fence, the adjacent landowner and the inspector should be consulted regarding acceptable fencing materials . In all cases, the contractor will obtain permission to enter upon adjacent private land . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1148 Construction of fences intended to be located on the right-of-way line will be surveyed and staked prior to construction . If the locations of the right-of-way line or adjacent property lines are in question , the department will be consulted for assistance . All fences will be designed and constructed in a manner that does not adversely impact the sight distance for vehicles, especially near roadway intersections . In urban or developed areas, standard barbed -wire fences are not the preferred type . Developers and landowners can make use of many other fence types that will better fit the needs . The department will be consulted and will review specific requests prior to construction . The contractor will perform clearing and grubbing as necessary to construct the fence to the required grade and alignment . At locations where fence posts or anchors need to be imbedded in concrete, adequate bracing will be left in place until the concrete has hardened . The tops of all posts will be set to the required grade and alignment . Avoid cutting off the tops of treated wooden posts . All gates will be galvanized steel or factory- painted , unless otherwise approved . 10 .9 . 7 Cattle Guards In Weld County, cattle guards are used to keep cattle or other grazing animals off the right-of-way . New cattle guards constructed within the right-of-way will be in accordance with CDOT Specifications Section 611 and Standard Plans No . M -611 - 1 ( Cattle Guard ) . A written agreement similar to the agreement found in Appendix 8-C of the Weld County Code must be received by the Public Works Department prior to installation . The contractor will obtain permission to enter upon adjacent private land , if necessary, for construction and will make arrangements for temporary access with the affected landowner( s ) . The deck area of all cattle guards will be constructed of steel, and all hardware will be galvanized steel . The contractor will ensure that concrete has sufficient time for curing and strength gain prior to allowing traffic to use the new cattle guard . The contractor will be responsible for providing a temporary means of controlling cattle or other grazing animals during construction . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1149 CHAPTER 11 PERMITTING The following permits are issued by the Public Works Department or the Planning and Zoning Department, as indicated . Additional information regarding any of the permits, including application forms, can be found on the Weld County website . 11 . 1 TRANSPORT PERMIT The Transport Permit is issued by the Public Works Department and is required when vehicles using the County road network are overweight, over-sized , or both . It is issued for standard overweight or over- sized load vehicles and for oil rigs drilling in the County . Permit conditions or restrictions may apply to these vehicles and are listed on the application form . When a permit for this application is issued by Weld County, the permit is subject to the conditions described with the understanding that no liability is assumed by Weld County by reason of its issuance . With regard to the condition of roads or capacity of culverts and bridges, the applicant must examine and inspect the adequacy of roads and bridges for traffic movement . In case of an emergency, an authorized Weld County employee or an authorized agent may suspend the permit until emergency conditions have passed . ( See Weld County Code, Chapter 8, Article XV, Sec . 8- 15 - 10, et seq . ) 11 . 2 RIGHT - OF-WAY USE PERMIT The Right-of-Way Use Permit, issued by the Public Works Department, is a tool to help regulate unauthorized obstructions of, excavations in , and use of the County' s rights of way and easements by requiring permits for all construction activities within the Weld County rights of way or easement and provide for the subsequent restoration upon completions . A Right-of-Way Use Permit grants a permit holder permission to occupy, excavate, survey, perform locations, or construct facilities within the County rights of way or easements and provide for the subsequent restoration upon completion . ( See Weld County Code, Chapter 8, Article XIII , Sec . 8- 13 - 10, et seq . ) Right-of-way Use Permit instructions and application can be found at : https ://www . weld .gov/Government/ Departments/ Public-Works/Permits/ Right-of-Way- Permits . 11 . 3 ACCESS PERMIT Land use, natural resources recovery, general utilities, and development have impacts on County roads . The requirement for Access Permits, issued by the Public Works Department, recognizes that the efficiency and safety of County roads depends on minimizing roadside interference and its detrimental effect upon the movement of traffic . The Access Permit sets out minimum requirements for the design , construction , and maintenance of accesses . ( See Weld County Code , Chapter 8, Article XIV, Sec . 8- 14- 10, et seq . ) 11 .4 GRADING PERMIT The Grading Permit, issued by the Public Works Department, is a tool to ensure that the County has reviewed the grading plan , the erosion and sediment control plan , and the utility map for proposed construction activities with the goal of avoiding potential damages . A Grading Permit grants the Permit Holder permission to conduct construction activities within the requirements of applicable state regulations and provides the County with sufficient oversight to minimize the potential for offsite damages . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1150 A Grading Permit will be required if disturbing more than one acre or any earth disturbance in an MS4 area per the MS4 criteria within this document . ( See Weld County Code, Chapter 8, Article XII , Sec . 8- 12 - 10, et seq . ) 11 . 5 FLOODPLAIN DEVELOPMENT PERMIT The Floodplain Development Permit is issued by the Planning and Zoning Department . ( See Weld County Code, Chapter 23, Article XI, Sec . 23 - 11 -200, et seq . ) WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE 1 151 CHAP TER 12 VARIANCE REQUESTS The County recognizes that in certain limited instances it may be exceptionally difficult to conform to the criteria set forth in this manual and the Weld County Code . The County will consider requests for variances on a case - by-case basis . The variance request will be submitted in a written attachment to the initial submittal of construction plans . Drainage variances are addressed in Section 8- 11 - 160 of the Weld County Code . All other requests will consist of the following : 1 . Identification of the criteria or Weld County Code section to be waived or varied 2 . Identification of the construction criteria adhered to 3 . Justification for the variance, which will demonstrate the following : • Hardship is created if the variance is not approved . The hardship shall be specific to the subject property, rather than general in nature such as cost, and shall not have been self- imposed by the applicant or their predecessors in title to the property . • There will be only minimal impact on public safety . • The variance is not contrary to best engineering practices . • The variance is not contrary to the intent and general purpose of these criteria and the Weld County Code . • The variance does not result in a significant impact to the public due to maintenance of the improvement . • The variance does not result in a significant impact to the aesthetic appearance of the improvement . • The variance is the minimum exception from the criteria necessary to afford relief from the hardship . • The variance is reasonably necessary for the health , safety, and welfare of the public . The variance request shall be prepared , stamped , signed , and dated by a professional civil engineer licensed to practice in the State of Colorado . Requests will be reviewed by the Public Works Director or his/her designee . The Public Works Director, or his or her designee, shall only approve the variance request if the applicant has demonstrated the justification required above . The Public Works Director reserves the right to deny, or allow his or her designee to deny, any request for variance if doing so is in the interest of public health, safety, and welfare . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGF 1152 This page intentionally left blank . WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA PAGE I 153 APPENDIX A - Weld County Drainage Basin Map WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA APPENDIX C - CDOT Operations and Maintenance Plan Guidelines WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA APPENDIX E - USDCM 2007 Runoff Coefficients WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA APPENDIX F - Rational Formula -Based Modified FAA Procedure WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA APPENDIX H - MS4 Pollution Prevention Plan Checklist and Manual WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA APPENDIX J - Weld County Standard Details WELD COUNTY ENGINEERING & CONSTRUCTION CRITERIA Hello